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Clark, W. C. 1961. A revised classification of the order Enoplida (Nematoda). New Zealnd Journal of Science. pp. 123-.
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Rothamsted Research is a Company Limited by Guarantee Registered Office: as above. Registered in England No. 2393175. Registered Charity No. 802038. VAT No. 197 4201 51. Founded in 1843 by John Bennet Lawes. SYSTEMATIC AND MORPHOLOGICAL STUDIES ON SOME ENOPLIDA (NEMATODA) WITH SPECIAL REFERENCE TO THE SOIL FAUNA OF NEW ZEALAND
by
W. C. CLARK, M.Sc. Hons. (N.Z.), D.I.C.
A
THESIS PRESENTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
in the Faculty of Science of the University of London
Aoril 1961 Deoartment of Nematology, Rothamsted Exoerimental Station, Harpenden, Herts. ABSTRACT
This study falls in two parts, systematics and mor- phology. Systematics. The classification of the order Enoplida (Nematoda) is revised. At the subordinal level the classifi- cation is nrimarily based on the nature, number and Position of the oesophageal glands and their ducts. Five suborders are recognised; Enojlina, Alaimina, Dorylaimina, Tricho- syringina and Diectonhymatina. The new features of the classification are:- Alaimina established for the Alaimoidea and the Diphtheronhoroidea on the oesophageal and male sexual characters. The similarities between the Diphtherophoroidea and the Dorylaimoidea are considered to be due to convergent evolution. On oesophageal characters the Mononchidae are removed from the Tripyloidea and together with the Bathyodon- tidae form the Mononchoidea within the Dorylaimina. The Bathyodontidae is formed of genera previously placed in the Nygolaimidae which possess a cylindroid oesophagus, adhesive organs and a mononchoid stoma. The definitions and constitu- tions of the families Nygolaimidae and Belondiridae are modified to make these families more homogeneous. The Mermithidae are Placed with the Trichuroidea in Ward's Trichosyringina thus uniting all the families with the Oesophageal glands in the form of stichocytes. The probable course of evolution in the soil dwelling enoplids in general, and the Mononchidae in particular is described. Morphology. The monorchic male reproductive system of the Alaimidae, and the two types of oesonhago-intestinal junctions in the Mononchidae are described for the first time. New species in the genera Amphidelus, Mononchus, Iotonchus, Cobbonchus, Mylonchulus, Pungentus, Longidorus, Sectomema, Dorylaimellus and Actinolaimus are described. A new leptonchid genus is erected, and its type species described. Existing snecies of the genera Cryptonchus, Mononchus, Prionchulus, Iotonchus and Cobbonchus are re- described.
CONTENTS
I. Introduction Material and Methorls 1. Materials 2. Scqn-fling iochnicluo and Procedure 3. Storage of Sauulas 4. Extraction of samils 5. Fixation 6. Mounting 7. Examination 8. Measurements III. Higher Taxonomy 1. A Revised Classification of the Order Enoplida (printed) 2. The Relationships of the Soil Dwelling Eno'ilids .1V. Suborder Enoplina 1 Family Ironidae V. Suborder Alaimina 1. Description of Anrnhidolus suiralis n. sp, 2. The Male Reuroductive System in the Alaimoidea VI. Suborder Dorylaimina ; Family Mononchidae 1. Introduction 2. The Mononchidac and Biological Control 3. The Oesouhago-Intestinal JuncEion in the Mononchidae (Enoulida, Numatod-1) (printed) 4. Re-descriptions of Mononchus truncatus Bastian, M. pauillatus Bastian and Prionchulus muscorum (Duj-Irdin) (Enoulida, Norltoda). (printed) 5. The New Zealand Mononchie (Enoplida, Nematoda) I. The genera Mononchus Bastian and Prionchulus Cobb. (printed) 6. Tho Mononchidac (Enonli a, Nematoda) of New Zealand II. The genus Iotonchus (Cobb, 1916) Althorr, 1950. (printed) 7. Mononchid NomatoCa) of New Zealand Review of the genus Cobbonchus Andrassy, 1958 with descriptions of n.)w SDOCLDS. (printed) 8. The Mononchidae (Enoplia- Nimatoda) of New Zealand IV. The genus Mylonchulus (Cobb, 1916) Pennak, 1953 (printed) 9.. Evolution within the 11thonchidae VII. Superfamily Dorylaimoidea I. Dorylaiminae; Description of Pungentus maorum n.sp. 2. Actinolaiminae; Description of Actinolaimus zealandicus n. sp. 3. Tylencholaimina; Description of Longido2us taniwha n. sp. 4. Nygolaimidac; Description of Sectomena taiaha n.sp. 5. Blon,l.iridae; Description of Dorylaimellus monticolus n. sp. 6. Loptonchide; Decription of Amphorostomum saccatum n. gen. et SD. VIII. Conclusion References Appendix I Enoplid genera recognised in New Zealand sampls ACKNOWLEDGMENTS
I thank Professor B. G. Peters and Dr C. Potter for acting as my supervisors and for discussions and encourage- ment. I am grateful to the staff of the Department of Nematology, Rothamsted Experimental Station, for their kind- ness during my stay at that Institution. Especial thanks are due to Mr F. G. W. Jones for his encouragement, and to
Dr J, B. Goodey for much help, advice, and free access to his excellent library. Finally, I thank the New Zealand Deoartment of Scientific and Industrial Research for financial support. NOTE
References to figures) tables etc. are numbered consecutively in the type-written part, but each of the printed sections has its own series of figure numbers and so on. References to iublications follow the same scheme; all papers cited in the typewritten sections are listed in the section "References" at the end of the thesis. Papers cited in the orinted narts will be found at the end of the relevant' section. Section
INTRODUCTION
When this study was first considered the idea was to investigate the species composition of nematode faunas and the abundance of different species in soil and litter of a variety of New Zealand soils. Further, it was intended to investigate the effect of different vegetation regimes on the nematode fauna of the same soil types. It was also thought that it might prove instructive to examine the nema- tode faunas which have developed in the soils in the central part of the North Island of New Zealand. These soils are largely derived from showers of volcanic ash, the time of deposition of which has been recorded in recent times, or accurately determined by other workers using radio-active carbon dating techniques. These ash-showers may have caused cataclysmic destruction of the fauna when and where they occurred, and have influenced its composition since. They may also have acted as barriers to migration for a consider- able time. Lee (1959) has shown that the distribution of Megascolecine earthworms was influenced in this way. Given (pers. comm.) found a similar influence in the distribution of the Melolonthid beetles, and Forster (1954) recorded a similar discontinuity in the distribution of the harvest spiders of the suborder Laniatores. No attempt was made whilst in New Zealand to identify - 2 - any of the material collected. The collecting programme was worked out using Taylor's (1948) "Soil Map of "New Zealand" and the genetic classification of New Zealand soils included in it and in Taylor and Cox (1956). In practice the original aims proved unattainable because of the dearth of knowledge of the free-living nema- todes of New Zealand. The diversity of species encountered is illustrated by throe samples taken from Wharakohe Silt Loam (a mature podzol derived froril silicified claystones under A,athis australia Salisb. forest in a warm humid climate). The samples wore taken. under natural heath-type vegetation, from an 18-year old Pasoalum dominant pasture, and from a two-year old ryegrass--white clover pasture. Each sample yielded eighteen to twenty fairly common S10,3CiS, but only two or three species were common to any pair of samples, and none common to all. Only one species of the species examined was referable to a known species. In view of the diversity of species and the indications that the vast majority of them appeared to be n:w, and in some cases, required the erection of new genera and possibly new families, it became necessary to turn to identification and description of species rather than to continue with predominantly ecological studies as planned. Once the systematic study of the New Zealand species, and where necessary the European ones, was well in hand it - 3 - became apparent that the existing accepted arrangement of genera and species in some groups had become inadequate over the years. Much time, therefore, had to be spent incorpora- ting new information, re-examining many accepted concepts and modifying the taxonomy to fit. mild steel rubber hose
1.5 in. o.d. stainless steel tubing—
-mild steel brass
_tempered _ steel
Fig. 1. Construction of the soil sampler. Section II
MATERIALS AND METHODS
1. Materials
All the New Zealand material examined was collected by the author during the period January to May 1958. Of the material from sites outside New Zealand, some was collected by the author, but much had been collected by other workers; most of it was already in the slide collection of the Department of Nematology, Rothamsted 'Experimental Station. A few specimens were borrowed from workers outside Britain. 2. Sampling Technique and Procedure As pointed out in the introduction, one of the original purposes of the study was to compare the abundance and siecios comnosition of nematode faunas under different conditions of soil type and vegetation. Therefore, an attempt was made to take sam3les of comparable size. A tubular soil sampler (fig. 1) was constructed of stainless steel because of the ease with which this material may be kept clean and the risks of cross contamination of samples reduced. The sampler was thrust into the soil to a depth of six inches, rotated, bent over at an angle to break the soil column, and withdrawn. The cutting edge was purposely made narrower than the internal diameter of the sampler body to reduce compaction of the soil core. It also served to grip the core and facilitate its removal from the ground. After - 5 - withdrawal from the soil, the s7.m)12 was inverted, and hold nt an angle. When the soil core wa.: lightly prodded it slid down the tube and was usually recovered intact. The core waS then cut with a knife into 0-3 and 3-6 inch 11-igths. The sam)ling procedure was ropeated so that three cores were taken at each depth. Each core had a volume of approximately 50 ml., the three cores for each level giving a total sample volume of 150 ml. Thu sar:iples from the different levels were )laced in separat polythene bags, and if xtraction would not take place within the next few days, the bags were sealed in a match flame. An embossed motal "Talabel" tag included in each bag to provide a permanent label un- affected by moisture or abrasion. The field record of site information included- 1. Date of sampling. 2. Name of locality. 3. Man reference to the New Zealand 1 in. to the mile topographic sheets, with a brief description of site, notingz- (a)elevation. (b)Aspect. (c)Angle of slopa and whether convex or concave. (d)Water logging etc. 4. A list of the dominant plant snecies present. 5. The soil typo, after comparing with the descriptions - 6 - given in the relevant New Zealand Soil Bureau Bulletin, or if such a Bulletin had not been published, a description of the soil profile down to 2 ft. so that the soil type could be determined later. (Often nedologists accompanied me to ensure that the samples were taken on typical sites and to provide local information about the history of the area and the whereabouts of different classes of vegetation.) 6. The sample numbers and the depths to which taken. 7. Any other information which might prove useful later (e.g., fertilizer history, pH.). Where samples could not be taken with a core samnler, a fern trowel was used to give a sam-ple of the same volume. Litter, moss and liverwort samples were only approxi- mately 150 ml. in volume es it was not possible to easily standardise the sample size of this material. The great variation in water content made weight impracticable as a measure and the degree of compaction and type of litter influenced the amount of material in a given volume. 3. :tor _age of Samoles At the outset it W7S realized that the time which would elapse between sampling and extraction might well cause much variation in the results. To investigate this 18 0-3 inch cores were taken from an apparently uniform patbh of grass- - 7 land and each bagged and sealed separately. On returning to the laboratory, six of the cores were separately rubbed through a coarse sieve, the grasses teased out, the whole sample set up in a Baerman funnG1 in the usual way (see 4 below) and allowed to stand for 24 hours. Then the total number of nematodes emerging was counted and the types present noted. The samples not extracted immediately were placed in a refrigerator and kept at 4°C. - 1°. At weekly intervals three samiles were removed and extracted as before. When, four weeks later, the last samles had been extracted, the results showed that the number and, as far as could be determined, the species extracted did not very over this period any more than the samiles extracted immediately after samlling varied among themselves. These results are in coord with those obtained by Overgaard Nielsen (1949) and Oostenbrink (1960). 4. Extraction of Samples The extraction procedure used was as follows:- 1. Rub sample through coarse sieve, tease out roots, Pick out stones (the three cores being mixed in the process).
2. Transfer sample to two, six-inch funnels with fine cotton gauze supported on wire gauze. The metal label always accompanied the sample. The level of water in the funnel was adjusted so that it came - 8 - well up into the sample. 3. Thoroughly clean sieve. Discard original sample bag. 4. After 22 hours the nematodes were run off into Petri dishes.
5. The cotton gauze and the soil were discarded, and the funnel and wire gauze support washed in cold water before they could dry, possibly leaving some nematodes adhering to them. The apparatus was then washed in boiling water llus detergent, and then thoroughly rinsed in cold water. Thorough washing being regarded as an important precaution against cross-contamination of samples. Because the mesh of the gauze was not fine enough for some soils this procedure did not give as clean samples as is desirable. Toilet tissues would have been much better and cheaper. 5. Fixation After running off the nematodes in a little water into Petri dishes, these were examined under the binocular micro- scope for nematodes. The dish was then gently heated on .a hot plate and frequently examined to chock the condition of the nematodes, as soon as they were "relaxed" heating was stopped. The contents of the dish were then transferred to a 3 x 1 in. tube via a small clean funnel. When the contents of the tube - 9 - had settled, the volume of water was reduced with a pipette. An equal volume of double strength F.A. 4:10 (Goodey, 1957) added, a label inserted, the tube corked and shaken. Enoplids fixed in this way remained in excellent condition for 3 years, but in the Tylenchida the spears had mostly dissolved, or at least become invisible long before this period of time had elapsed. The problem of the dis- appearance of spears in the orthodox acidic fixatives might be overcome by fixing in these solutions for a short period only, say 24 - 48 hours, and then transferring to a non- acidic preservative such as a 1% aqueous solution of propy- lene nhenoxetol (Owen 1955, Owen and Steedman 1956). 6. Mounting Before mounting the nematodes were transferred to glycerine according to Baker's (1953) method. It was found advantageous to add a little methylene blue to the first solution and to vary the time in this solution according to the degree of staining required, and the facility with which the different snecies took up the stain. Usually nematodes remained overnight in the pure glycerine in the oven as this resulted in better °reparations. Whole mounts were made according to the method in Goodey (1957). Preparations of carts of nematodes for en face view of the lip region, transverse sections for examining the thickenings of the oesophageal lumen and the type of incisures etc., were also - 10 - made as described by Goodey, but it was found that better results were obtained from specimens which had been trans- ferred to glycerine by Baker's method, rather than using the quick lactophenol-cotton-blue method. 7. Examination Manipulations requiring only moderate magnifications were done under a Leitz stereoscopic microscope with a traversing head. When higher magnifications were needed, examinations were made under a Lcitz Ortholux microscope u-dng Apochromatic objectives. Incident illumination was used in addition to transmitted light. Drawings were made with the assistance of a reflex prism made specially for the Ortholux microscope. 8. Measurements Measurements were made in different ways for different purposes to keep the margin of error of the same magnitude throughout. Length measurements were made as described in Goodey (1957) always using a magnification of 125-200 diameters. Measurements of body width were made using a Leitz screw micrometer eyepiece a .d a magnification of 600 diameters. Measurements of stoma length and cuticle thickness wore made with the same apparatus but at a magnification of 1,350 diameters. Measurements are given according to the de Ian formula which is almost universally used in descriptions of plant - 11 - parasitic and free-living nematodes. The de Man formula has largely superseded the Cobb formula, probably because it requires fewer measurements (a dubious advantage) and because of the simpler type-setting in bublications than required by the Cobb formula at its simplest. - 12 - 2. The Relationships of the Soil Dwelling Enoplida
In the previous section the systematics of the Enoplida as a whole were treated in an orthodox fashion. Here it is proposed so discuss the relationships of the soil dwelling groups-in more detail. Because of the use of the "type method" in systematics, the typo taxon is allays discussed first in any sequence of taxa as if it were necessarily typical of the grou or the most primitive. Such procedures often serve to obscure relationships rather than to clarify them, In figure 2 the deduced phylogeny of the soil-dwelling enoplids is set out. In the construction of this scheme considerable importance has been laced upon the form of the oesophagus, the number and Position of the oesophageal glands and their ducts, the stomata Armature, the adhesive organs (= caudal glands) and the male reproductive system. From this information it is possiblc to set out what appears to be the probable ohylogeny of most groups, though the Positions of the Diphtherophoroid a and the Campydoridae remain doubtful. I have considerable reservations about the validity of the Opailaimidae. The enoploid stock probably branched to give rise to the Alaimina-Dorylaimina and Tripyloidea stems. The Trioyloide:i retained the enoploid fcies to the greatest extent, retaining the ddhesive organs throughout and LEPTONCHIDAE DORYLAIMIDAE
OPAILAIMIDAE
BELONDIRIDAE =r.`"*?CAMPY.DORIDAE
NYGOLAIMIDAE
ONONCHIDAE DIPHTHERO - PHOROIDEA BATHYODONT I DAE
ALAIMOIDEA
TRIPYLOIDEA
ENOPLikA
Fig. 2. Phyletic arrangement of the soil-dwelling Enoplida, with the morphological features shown on an overlay. ONE TESTIS NO PRERECTUM . NO ADHESIVE ORGANS rg st om 7
a 11 oes
red 44 . gl
uced a and , cell un 11 arm s li il ed 1
I 0 [ l EE. F. 1 erEr
. OES.GLAND CELLS [D(4AL5 AREly larPHAGEALEHIasAft2 CELLRING1_31.I 4E12OES. GL. DUCT ANT 113 PLR
The superficial similarity between the Dorylaimoidea and the Diohtherophoroidea is considered to result from convergent evolution rather than an immediate common ancestry. The ohyletic scheme outlinod above rests mainly upon the irinlied homology between the mural tenth of less evolved groups and the hollow, tubular axial spear of the higher groups. This may .hear unjustified, but the idea is not now. Chitwood and Chitwood (1937) o. 9 state "A tooth may be transformed into a stylet in which case this structure may be termed an onchiostyle." Chitwood later (1938) again dis- cussed the matter briefly. In the Dorylaimidae the spear (or onchiostyle) is a hollow cylinder with an oblique terminal aperture. The whole of the spear, guiding ring, spear extensions, and stomatal lining as well as the exo-cuticle are shed at each moult (fig. 4). The new spear is formed according to Thorne and iWanger (1936) in a single cell in the left submedian wall of the oesophagus and later migrates anteriorly and at the moult moves into its final position and establishes connections with the now guiding ring, and spear extensions (fig. 5). Because the guiding ring is continuous with the stomatal lining (Goodey, 1961) all food p,,Isses through the lumen of the spear. Exactly the same processes are involved in the replacement of the mural tooth Fig. 6. A toulting larva of Iotonchus maragnus Clark with a new stomatal lining forming around the old lining which is being shed. - 17 - of the Nygolaimidae at each moult. Thorne (1930) shows this in his figures of Nygolaimus pachydermatus. In Nygolaimus the tooth is hollow, but has no terminal aperture. All food passes from the stoma into the oesophagus through the unobstructed passage betweon the tooth and the stoma' wall. In S ctonema spp. the tooth appears to be solid. The significance of the Nygolaimidae in the evolution of the dorylaimoid spear was first noted by Cobb (1922) when he stated that Nygolaimus "may possibly be regrded as a transi- tional form". In the Mononchidae the whole stoma and oesophageal lining is cast out at each moult, end a new stomatel capsule is formed behind the old ono before it is shed (fig. 6). The developing stoma is surrounded by ectodermal tissue as is the developing dorylaimoid spear. The Mononchidao are, how- ever, a specialised group, and the form of the stoma militates against its being formed more posteriorly in the oesophagus and then migrating into the definitive position. Unfortunately nothing is known of the behaviour of Mirolaimus during moulting or the origin of the "tooth". What h> opens in Ironus ignavus is illuminating. Here the stoma is surrounded 9.t the anterior end by three inwardly projecting teeth. Again, the teeth, stomatal and oesophageal linings are shed at each moult (fig. 7). The new teeth already in existence before the moult are formed behind the old teeth in the Fig. 7. A moulting larva of Ironus iznavus Bastian showing the moulted cuticle and oesophageal lining. The moulted teeth are not visible at this level of focus. Fig. 8. Ironus i avus (Bastian) larva showing the developing teater de Man, 1884 )4) - 18 - tissue of the oesophagus (fig. 8) and migrate forward in a manner which, as de Man (1884) noted, is exactly comprable with the spear of the dorylaims. The chief differences between the movements of the teeth in Ironus and the sp ,ars of dorylaims are th- t, in the former, three elements are involved instead of that all the migration takes ulace through the oesophageal tissue rather than partly at least through the oesophageal lumen. -19 - Section IV
Suborder ENOPLINA Family IRONIDAE
Subfamily IRONINAE Ironus ignavus Bastian, 1865 (for literature see Micoletzky, 19259 .108). Reefton, New Zealand. 4 2.7_ s . L = 1.76 mm (range 1.65-1.89), a = 44-48; b = 4.55-5.09, c = 3.44-3.91, V = 39.4-43.7 I have compared these specimens with material collected near Falmouth, England (type locality of I. ignavus) and can find no differences between the two -Populations. The New Zealand material comes from a sphagnum bog near Reefton in the Buller district. In fixed specimens from both populations I ftwe been unable to detect the glandular structure in the oesophageal region figured by Cobb (1918). Subfamily CRYPTONCHINAE Chitw. & Chitw., 1937 Cryptonchus Cobb, 1913 Ironidae, Cryptonchinae. Cuticle with very fine transverse striae. Amohids oocket-like, apertures transverse slits about as wide as stoma. Lip region not offset, consisting of six inconspicuous lips each bearing a single small papilla. No cephalic setae. Stoma long, tubular, composed of three abutting, longitudinal, sclerotizod plates and bearing two small dorsal teeth at the posterior and. Oesophagus - 20 - cylindroid without a terminal bulb, but bearing a rather rounded, glandular sphincter at the oesophago-intestinal junction. Intestine simple. Vulva near middle of body, ovary single, anterior, reflexed. Eggs large (length about four times body width), only one in uterus at a time. Cuticular lining of rectum prominent. Tail tapering, caudal glands °resent, terminal duct seen only in tape species. Males unknown. Type species; Cryptonchus nudus Cobb, 1913 Cobb (1913) founded the genus Cryptonchus for the reception of a species which ho named nudus which he had found in two localities in the United States. Ditlevsen (1911) described the same species from Denmark under the name Cylindrociaimus tristis. The synonymy of this species is given below. Cryntonchus tristis (Ditlevsen, 1911) Cylindroclaimus tristis Ditlevsen, 1911 Cryptonchus nudus Cobb, 1913 Cylindrolaimus tristis W. Schneider, 1922 Ditlevsenia tristis Micoletzky, 1925 Cryptonchus tristis Filinjev, 1936 Cryntonchus nudus Goodey, 1951 This species has been recorded from two localities in the United States and from Denmark, Southern Sweden, Poland and Germany, from freshwater habitats :bout the roots of ------Fig. 0. Cryptonchus abnormis (Allgen). A female; B en face view of head; C ditto at- level of amphids; D section through mid-rAion of stoma; E section section through base of stoma showing tooth; F section through oesophagus; G8:11 head in lateral and dorsal views; I oesophago-intestinal junction; J ventral view of vulva;K anal region of female. - 21 - plants. Cryptonchus abnormis (Allgen, 1933) Schuur-Stekh., 1951 Fig. 9 A-K Cvlindrolaimus abnormis Allgen, 1933 Gymnolaimus exilis T. Goodey, 1951 nec Cobb Cryptonchus abnormis Schuurmans Stekhoven, 1951 Gymnolaimus exilis, Andrassy, 1956 nec Cobb Measurements oo Reefton, New Zealand. -1-1- n = 20. L = 1.756 mm (s = - 0.057 mm) (range 1.62-1.85 mm; a = 46-70; b = 4.35-5.13; c = 3.26-3.72; V = 40.3-45.3. Cuticle and subcuticic 1 ,u thick; cuticle with vzy numerous annulations, not resolvable into rows of dots. No lateral fields. Lip region not offset, but head region constricted slightly about one hoed-width behind lip region. Lips six, inconspicuous e.ch with a single papilla. No cephalic setae. In en face view (fig. 9 B) oral aperture is hexagonal. Amphids situated one and a half head-widths behind lips, pouch-like with transverse slit-like apertures a little wider than stoma, :a.ppearing crescentic in on face view (fig. 9 C). Stoma about 6 times as long as width of lip region, tubular, of uniform diameter anterior to teeth, consisting of three sclerotized abutting plates, lumen some- what triangular in cross section (fig. 9 D) reminiscent of the Mononchoidea. Stoma lumen constricted near posterior - 22 - end by a ventral thickening of the stoma wall and an opposing dorsal tooth. In lateral viw there is a second smaller dorsal or sub-dorsal tooth a iitl posterior to the larger one but this w7..s. not visiblc, in hand cut trans- verse sections. A short distance behind the teeth the lumen narrows and becomes the oesophagus proper. The whol of the stoma is embedded in oesophageal tissue, which forms a thin sheath anteriorly but which thickens a little anterior to the teeth, end then remains th same width throughout its lmgth. Nerve. ring indistinct, occurring at 38 per cent of oesophageal length. Oesophago-intestinal junctionith a large, rather globular, glandular sphincter musclo with a small oosophago- intestinal valve projecting from its posterior face into the lumen of the intestine. Intestine simple. Vulva a bi-crescentic, transverse slit, with slightly thickened, usually protuberant lips. Vagina somewhat muscular extending across almost a half body-width. Ovary reflexed through a short distance usually consisting of less than five occytes, nuclei prominent. Uterus comlletely filled by a single egg, Egg length equal to four times body-width. No prerectum. Rectum straight, length equal to anal body width, with a prominent cuticular lining. Anus a transverse slit. Tail long, slender, tapring uniformly to - 23 - filiform tip. Three caudal glands present but no terminal duct seen. Caudal cuticular pores not seen. Larvae resemble female. Males unknown. Material from sphagnum swamp, RJ.ofton, New Zealand. Rs=rks. I hive examined the slide bearing the specimens recorded by T. Goodey (1951) from Java and have compared the with the original description of Gymnolaimus exilis (Cobb, 1893) Cobb, 1913, and find that the material is definitely not raferabLe to Gvmnolaimus, because of the toothed nature of the stoma and the uniformly cylindroid posterior part of the oesophagus. Andrassyls use of G. axilis for this species appears to be based on Goodeyls misidentificItion. Most of my specimens have a largo number of small oval bodies in the colom, possibly Soorozoa, apparently similar to those recorded by Andrassy. Distribution. This species has an unusual distribution, being known only from the Lower Congo; Ivory Coast; Buitenzorg, Java and 1\1:1,/ Zaalnd. This discontinuity is Probbly explainable in terms of collection failure. The two species of Criptonchus are readily separated on the basis of tail length; in C. tristis c = 11-14.3, but in C. abnormis c = 2.9-3.7. -24- Section V
Suborder ALAIMINA Family ALAIMIDAE
1. Description of Amphidelus sniralis n. sn. Amphidelus spiralis n.sp. Figs. 10 A - F. Holotype L. = 1.21 rpm. a = 50; b = 3.61; c = 17.5; V 22 70 Allotype 4eL. = 1.21 mm. a = 65; b = 3.84; c = 17.3; T 52 Paratypes (n = 6) L = 1.26 mm. (range 1.13 - 1.43 mm) a = 45 - 59; b = 3.61 - 4. o0; c = 16.9 - 18.6; v13-2266_71
dbii(n = 5) L = 1.225 mm. (range 1.16 - 1.32) a = 62 - 66; b = 3.64 - 3.94 mm; c = 17.3 - 21.1; T 51-57 Slender nematodes which taper gently from near the middle towards both ends. When killed with gentle heat they lie in a plane spiral. Cuticle and subcuticle 1.5 p thick, smooth. No cuticular pores observed on any part of the body. Lin region somewhat angular, narrowing anterior to the outer circle of ten cephalic papillae. Inner ring of cephalic papillae not seen. Lips equal, almost fused. Aperture of stoma triangular in en face view. Amphid apertures large, oval, placed well bpck on neck region; amnhids pocket-like and communicating posteriorly with sensillae which are situated about one body-width anterior 50P
50P IF so p I BCD
Fig. 10. Ainphidelus spiralis n. sp. A lateral view of head, B male tail, C female tail, D spermatozoa within"packets" in vas deferens, E oesophageal region, F reproductive tract of female. - 25 - to the excretory pore. Stoma short, small, lying wholly anterior to the oesophagus. Oesophagus slender anteriorly, widening gradually posterior to the nerve ring (which occurs at about half its length) to form a ra ther pyriform posterior bulb. Oesophageal gland cells apparently seven in number. Oesophago-intestinal valve short and broad. Intestine passes to the right of the reproductive tract. No definite prerectum in either sex, but in the female the intestine narrows slightly a short distance anterior to the rectal sphincter (fig. 10D). Female Vulva a transverse slit; vagina directed slightly anteriorly and extending across less than half the body width. Uterus, oviduct and ovary single, and anterior. Uterus and oviduct outstretched. Ovary reflexed half-way back to the vulva. Only one egg in the uterus at a time. Eggs 73 x 20.5p . Rectum straight, length slightly more than anII-body-width. Tail conoid with a short mucro on tip. Male Testis single, outstretched, about one quarter as long as vas deferens. Spermatocytes arranged in a single or double row within anterior wIrt of testis. Posterior pert of testis filled with randomly arranged fusiform spermrlto- cytes. Vas deferens set off from the testis by a slight constriction where the wall of the tube appear slightly thickened. In the vas deferens the spermatozoa appear to be enclosed in small packets (fig. 10E); the membrane about - 26 - them may be the cell w 11 of the prim ry snermatocyte. Generally the vas deferens is wider than the testis (half to two-thirds of the body width)5 no ejacuatory duct is nresent, only a very slight narrowing of the vs deferens near the snicules. Sicules p.irod , free, equal, straight with the dorsal ends fl--.ring out slightly. Spicules set almost at right angles to the body axis. Ventral tips of spicules closer together than the dorsal ends. Supplements four, low-mammiform, ventro-median, approximately equidistant. Adannl member unwired. Tail similar to female ventrally curved, conoid with a terminal mucro in most specimens. Specific differentiation. Amohidelus spiralis n, sp. is readily distinguished from all other described species in the genus by the single unnaired anterior ovary and the complete absence of the posterior branch of the reproductive tract. The reduction in head width anterior to the outer ring of cephalic aepillee and the mucronate tail fllso serve to distinguish this sp3cios from most others.
Type slides, Holotype, llotype and p..ratypos in the nematode collection, Entomology Division, D.S.I.R., Nelson, New Zealand. A paratype male and female in th,i slide collection, Hematology Department, Roth=sted Exoorimental Station, Harpenden, England (slide No. 193/2/1). Tyne Locality. igitaanga Saddle, N.Z.M.S.1., N 100, 453170, 520 m., in liverworts and mosses in Knightia excelsa R. Br, - - 27 - Weinmannia racemosa Linn.f, - Brachyglottis repanda Forst, forest. Remarks. , The single prodelphic gonad in the female is unique in this genus. .Spermatozoa within the uteri of the females all appeared much larger than the spermatozoa enclosed in packets within the vas deferens in the males. All males examined had spermatozoa in the vas deferens and some females had an egg in the uterus material collected in April. 2. The Male Reproductive System in the Alaimoidea Chitwood & Chitwood (1940 & 1950) discussed the male reproductive systems found in the Nematoda. However, as they state that in the Enoplida all males except those in the Trichuroidea and Dioctophymatoidea have naired testes, and that ejaculatory ducts, usually prominent, are found in all known forms other than the monorchic groups mentioned above, they evidently did not consider the Diphtherophoroidea or• the Alaimoidea. As far as can be ascertained all males in these two groups are monorchic, with the testis out- stretched anteriorly, and without conspicuous ejaculatory ducts. No accounts of monorchic reproductive tracts of soil dwelling enoplids have been found, and in an attempt to make good this deficiency, the system as found in representatives of the Alaimidae is described here. This account is based on 12.
Figs. 11 & 12. Amphidelus spiralis n. sp. Fig. 11. Schematic representation of the male reproductive system. Fig. 12. A anterior end of testis showing spermatogonium and spermatocytes; B spermatocytes in posterior part of testis; 0 one packet of spermatozoa. - 28 - males of Alaimus glissus Thorns, 1939, Amphidelus soiralis n. sp, and males of four other undescribed species of Amphidelus from New Zealand. (a) The Reproductive Tract The main features of the alaimid male reproductive system are shown in figure 11. The single testis is out- stretched anteriorly, sand divisible into two distinct regions; the anterior germinal region where the spermatocytes are produced, and the nOsterior often wider region (the "seminal vesicle" of the Chitwoods) where the spermatocytes change their form. The "seminal vesicle" is marked off from the vas deferons by a slight constriction and a sphincter muscle, the degree of development of which varies from species to species. The vas deferons is very long and shows no sign of an ejaculatory ducts In most onoplids the vas deferons is constricted near the first supplement and behind this has rather thicker walls, but in the claims there is only a gradual decrease in width a short distance anterior to the spicules. The course of spermatogenesis has not been studied in detail in this group, but it appears to differ from the usual sequence of events and appears to be rather similar to that described by Cobb (1928) for 6pirina narasitifera (Bastian). Chitwood (1940) has said that this account is based in part upon a misinterpretation. In the germinal -29- region of the testis the most anterior cell (spermatogonium?) is always single and apical. Bhind. this li es a series of sp:Jrmatocytes. In young males thos•J are arranged in a single row (primary spermatocytes ?) but in more mature specimens thy lie in two rows (secondary spermatocyte ?) (fig. 12A), As they eniarg in the posterior part of the germinal region they once more iie in single fiL-J. In the germinal r egion the germ cells all have large nuclei with smell darkly pig- mented bodies ) probably chromatin) and granular cytoplasm. In the seminal vesicle the spermatocytas become fusiform) the length g breadth ratio of the spermatocytes varies from species to soecies; the nuclei become invisible and, th e cytoplasm non-granular (fig. 12B). In the anterior part of the vas deferens the spermatocytcs undergo repeated divisions to form a large number of small spherical cells (primary spermatids ?) which gradually increase in size as they pass down the vas deferens. The spormatids (?) are enclosed with- in membranes or -,ackts (figs. 10E and 12C). The membranes apnuar to be the old cell wall of the secondary spermatocytes. About halfway down the vas defer:ms, the scermatids suddenly become much smaller and more numrous within the packets but as they move further down th, vas defer,ens) their form er size is rostorod, These slpherical bodies are the spermatozoa. Chitwood (1940) claimed that the small bodies reported by Cobb (1928) which appear to have been similar to the onas
C
0 t
D E
Fig. 13. Diversity of spicule form in the Alaimoidea. A Amphidelus spiralis aa. sp., B Amphidelus sp. ex Lake Mahinapua, C Amphidelus sp. ex waitaanga Saddle, Amphidelus sp. ex Wharekohe, E. Amphidelus sp. ex Barrytown. - 30 - under discussion were not spermatozoa but secretion globules in the walls of the vas deferens. In the present case the whole lumen of the vas deferens is filled by these bodies. In a number of packets there is a darker area but as far as can be determined these darker patches indicate a local absence of spermatozoa.
In that there apear to be too many divisions between the production of the spormatocytes and the definitive spermatozoa, this description conflicts with the normal notion of snermatogenesis, but will serve for the gross morphology of the system. The course of spermatogenesis requires further investigation with more suitably stained material. (b) The soicules Up to the present, apart from Alaimus filiformis Daday which Thorne (1939) regarded as a species inquirenda, the spicule shape has been remarkably uniform in all described males of Alaimus and Amphidelus. All species have straight spicules with slightly enlarged or flaring heads (figs. 13 A-C) similar to those of Amphidelus spiral's. The New Zealand material of the genus displays a diversity of spicule form hitherto unknown. At least two species have curved soicules with rather rounded slightly inflated heads (figs. 13 D-E). In all other characters these snecimens agree with the rest of the genus Amphidelus. This diversity of spicule form is - 31 - another way in which the Alaimina converge towards the Diphtherophoroidea, the other monarchic group with curved and straight srAculos. ih< Alaimina, however, show no sign of a gubernaculum. -32 -
6ection VI
Suborder DORYLAIMINA Family MONONCHIDLE
1. Introduction The mononchs were amongst the first free-living nematodes to be described when the study of free-living nematodes was in its infancy about the middle of the 1. ..st century. The first mononch, Oricholaimus muscorum was described by Dujardin in 1845; this was followed by several more species described by Bastian in 1865 which he placed in his new genus Mononchus. He also transferred Dujardin's spcies to this genus. In the years that followed many of Bastiants species were recorded from the various parts of Europe and several new SDOCLLS added to the list. Most of the European species were all referable to the genus Mononchus as at present constituted. The outstanding exceptions being Anatonchus tridentatus (de Man) and Mylonchulus brachyuris (Butschli). About the turn of thp century Cobb described a number of species which are now referable to genera other than Mononchus and Prionchulus. The landmarks in the systematics of the group are Cobb's 1916 and 1917 papers whore he first erected a number of subgenera within the genus. These were based on the different types of stomatal armature found in the group. Cobb was more concerned with the arrangement of the teeth - 33 - within the stoma rather than the shepe of the stoma itsalf. Over the years Cobb's arrangement met with general, but not universal acceotance. Micoletzky (1922) accented the sub- genera, but relegated many of Cobb's species to synonymy. Since Micoletzky's time a number of new species have been described, but th status of many snecies has long been in doubt. Andrassy (1958) revised the whole group and elevated all of Cobb's subgenera to generic rank and provided five new genera to accommodate species which did not fit Cobb's subgenera. At the generic level thare is littl criticism to offer on this arrangement. At the specific level, how- ever, much of his synonymisation appears arbitrary. Most of the work was done from the literature and not from specimens, and displays an over-eagerness to "tidy up" by naming species which the original authors hesitated to name, or by synonymising and not giving any reasons. For instance, the discussion of the variability of Mononchus trljncatus would have been more valuable if accor-lanied by a description and figures of the variation encountered. On the whole the napor was a considerable, advance, even if it did omit the fact that all of Cobb's genera had bean given generic rank by Ponnak (1953), and tht some, notably prionchulus, Ahatonchus and Iotonchus had been accorded this rank ._given earlier (Chitwood Chitwood, 1937, de Conninck 1939, Altherr 1950). The systematic position of the MononchjAge was discussed in -34-
Section III. Cobb (1917) discussed the biology and morphology of the group fully. The Mononchidae are a very widespread family occurring in soil, freshwater, cryptograms and forest litter. The odd records of them from marine environments, e.g., Wieser 1953, are readily accounted for as a result of having been washed out of their normal habitats by streams. Geographically, they have been found wherever they have been sought. They occur in high latitudes in the northern hemisphere, through the tropics and on the Antarctic continent itself. Whilst the family is widespread, not all genera are ubiquitous. Distribution at the generic level is discussed in subsection 9. Cobb considered the mononchs to mainly syngonic, but this seems to vary considerably from genus to genus. The New Zealand iotonchids mostly have males, and males aro known in all Now Zealand species of Mononchus. There seems to be no generalization of universal application to cover even a single genus in this respect. Ditlaysen (1911) observed that mononchids very frequently float when soil is placed in water. I have con- firmed this observation many times, and consider that it may be an important factor resulting in low estimates of soil populations where this possibility is not guarded against. -35 - 2. The Mononchidae and Biological Control Since Cobb's 1917 paper there has been scarcely a paper dealing with the Mononchidae which has not mentioned that some of them at least are nemativorous. The nemativorous habit has been much discussed and probably over-emphasised. One result of this was the two American studies of predation by mononchids. Steiner and Heinly (1922) investigated the biology of Mononchus papillatus and were able to devise culture methods for this species. They fed M. papillatus exclusively on nematodes (Rhabditis, Turbatrix and Heterodera larvae), but to obtain satisfactory cultures they had to include a small amount of soil which suggests that other micro-organisms form an essential part of the: diet. Larg , numbers of nematodes were eaten by this species under laboratory conditions, but apart from the Protozoa and bacteria which may have been present in the soil, no other food was offered, so a preference for nematodes as food was not established. My attempts to rear M. papillatus and Prionchulus muscorum in sterile silver sand using washed nematodes (Rhabditis, Aphelnchus, Aphalenchoidos and Ditylenchus spp.) as food were unsuccessful. Hesling (pers, comm.) has succeeded in keeping a culture of a Prionchulus sn. (possibly nunctatus Cobb) for over a month feeding them nematodes only. Thorne (1927) studied the use of naturally occurring Fig. 14. Part of an Iotonchus percivali Clark showing an iotonchid stoma, a tylenchid, and a pair of dorylaimoid spicules in the gut. - 36 - mononchids to control Heterodera schachtii infestations in sugar beet. H. was concerned with Mononchus paPillatus9 Mylonchulus sigmaturus and Myl. brachvuris. His data indicate a much higher proportion of mononchids to other nematodes than in Greet Britain but frequently most of the population was comosld of members of the genus Mylonchulus which rarely attack other nematodes. In fact, of the three, species investigated by Thorne, only M. nanillatus appeared to be nemativorous to any extent; the remaining species feeding mainly on rotifers and nrotozoans. I think the nemativorous habit has been exaggerated by the use of the Baerman funnel for extraction-. In this apparatus high densities of nematodes are built up , often for long periods in a small volume of water at the bottom of the funnel. The chances of other nematodes being attacked under these circumstances are probably much greater than in soil. In my c;x1 rience Anatonchus tridentatus is the most actively nemativorous of the British species. In New Zealand soils the Iotonchus sop. are active carnivores and pare commonly found (fig. 14) with nematode remains, and rotifer mastices in their guts. Even if the mononchs noss-ssed all the features attributed to them it is unlikely that they could exert any gree t effeot on Haterodera schachtii popu17.tions, because the H. schachtii larvae are only ox)osed to the predators for a Fig. 15. Part of a leptonchid showing a dense population of sporozoan oocysts. - 37 - r cla t ively short ) riod in the spring and ,2arly summer. Further, the life history of Nononchids, if N. papillatus is at all r oeressntativc, is of too long duration for them to be able to utilize the periodically. available larval heteroderas effectively as a food s)urce. Then too, because the two groups of nematodes had be =n, living together for a long . period, the two populations may be assumed to have reached some sot of balancc,, and the mononchs would have increased naturally if the conditions over the whole spectrum of their requirements were being met. If an esocially nemativorous mononchid SWJCies could be found which would thrive in gricultural soils, then it mig It be useful when introduced into a naw environment. A limiting factor may be th-:, susceptibility of mononchs (and lentonchids) to soorozoan infections (Thorne, 1927 and p.204 sub-section 5 (fig. 15)). If such an attempt is to be made it would be more realistic to try them against migratory root parasites, rather than the more sedentary Hetsrodera and Meloidogyne sop. which arc unavailable as food for long ocriods during the growing season. Fig. 16. Map showing the distribution of Mononchus spp.in New Zealand.
- 38 - Distribution of Ye-To Ze,Thd 1,7ononchuc The 'mown distribution pattern of the Now Zealand
species of :iononchus (fi'T 16) indicates that comosticolo and mesath:, 'ta.s are foi. st inhabiting species. N. composticoia is co=only found in forest
litter, nnd denus mo t commonly associated 7::ith Mosses and liverworts. Where two habtats are distinct as at Tutamoe these differences are clear cut. in the Tutamoe es c--Tiroc,ticolU-. ,,as extracted from forst fluor litter, and mesadenus was recovered from
losses and liverworts sera of't tree tunks. Often a certain amount of moss and liverwort ere found with the forest litter, and under these circuitanc two species occur together. itestriction of these species to either hatitat does appear to be absolute. M. rrobaill',, tus however , shows rio marked habitat preferences. It has been found in sub .._rjne forests where frosts are common and where snow lies for sev,eral weeks every year , and in areas where snow or )._Lost never occur. It is common in the litter of indigenous forest and amongst the fallen needles of exotic Iqs radieta e Don forests.
The pine needle fauna of Kaiangaroa For inte resting. because rc . -Drorazi was the doin-nt species, far outnumbering all the other species. A conc). niale
pecimen was found at this locality. The litter of Mononehus composticola C gerlachel G
•• mesadenus m major
a
•
•
Fig. 17. map showing the circum-south-polar distribution of four species of Mononchus. - 39 -
Finus forests may be rsgz:irc2cd as a un,311 ' in A " Zaland.
The circum-south pb12r c stribution of the "Mononc4us rim or - chp, grou-ou in 'acliJh 11:r 17. _as four
cis comi-Jrisin this are ciosein el2t7::d from mor i'oint of vic Mow 'Gnat t: obable existence of a. circum-sout polar grout' o f nena Lads ecies has esbablisl c it -would be of'eat interest from aooge Lr 1-licn] point of view to ex-min2
L.7rial from sul antectic islenf uolen,
Macquarrie, Aucklends, Ca ell; South nd Goun. Addendum The Lep;erolla specie mcntioned on :. 2C)-J, of the previous subsection has been describald by Ca nine: (1961) under ths name Le erella helminthorum. Fig. 18. Nap showing the distribution of Iotonchus spp. in. New Zealand. - 4o — Distribution of New Zealand lotonchus SD.Q.
The distribution of the You Zealand species of Iotonchus is shown in figure l'(]. It is noteworthy that apart from I. parazschokkei which is primarily a. forest litter and secondarily a soil dwelling species, all the other species have been found in podzolic soils. In most instances these have been gley podzols (the Wharekohe locality is the exce,)tion). The immediate difficulty is to decide wilther the factor which limits the distribution of these species is simply the water relations of the soils (all sites were rather wet), or if distribution is related to some other podological feature such. as pH. Fig. 19. World distribution of the genus Cobbonchus Andrassy. a. abrupticaudatus (Altherr) c. chauliodus Clark ; m. mauritianus (Williams) ; p. pounamua Clark ; ps. palustris (Cobb) ; r. radiatus (Cobb) ; t. teres (Cobb). - 41 - Addendum on the genus Cobbonchus
Since the foregoing was written Althcrr, 1960 has described Loponclius atru'oticnu(1atus (=Cobbonchus abruticoudatus) from the French Cameroons. Although Altherr remarked that his species is very similar to fllustris (Cobb), it aD:.e;:rs to me to be even closer to C. mauritianus (Williams), from which I am un==able to differ- entiate it. The record of this species helps to fill one of the gays in the distribution of this genus. It is significant that all known species are associted with very wet soils or sphagnum swamps not areas which i^ve been much examined for nematodes. For this reason it is likely that the distribution as recorded in figure 19 reflects collection failure rather than a truly discontinuous distri- bution. 9. EvollJtioh within Morl)nc_
T—e natL)ral consecienca of study of group of or anisms is the s:jrithetic of the study where an attery)t 1s --mie to weld ,:' of iqforNation ay.-2,i1,, b1s into a coherent whole. In this study an
attc made to clate t. mo,cnchid cnere to eac -i other in a y which rely ini.:ic,- to th ganral ,...ends of
evolution_ 1::ithin the groulD. the osent study this
process is bset with two mo yi1 lificuties which mu_st be clearly stted at the outset.
1. All evidence must he derive from neontoloy
as nematodes have left no useful D laeontological record. Because of this the time element cannot be considered.
2. VLst areas of the zarth' surface have iot been examined even cursorily for mononc2,
that evidence fromstribution patterns ss of
un1no,411 and genera, t
unrecorded may have to be incorporated at some future dato.
Althou a 1 have earlier (Section 111) included the
Mononehoidea in the DorylLli-uina _.era is no reason to believe that the ancestral mono_rc.:hids were darylaimoid. Cu morpholo _i_cal grounds it oppers trobable that tit- MONONCHUS MONONCHUS
IOTONCHUS PRIONCHULUS
SPORONCHULUS I I $ , g ,.. GRANONCH , . MYLONCHULUS I I I U I MICONCHUS BRACHONCHULUS ANATONCHUS I t) COBBONCHUS
TUBERCULATE NON-TUBERCULATE OES.-INT. JUNCTION OES7INT. JUNCTION ENOPLOID ANCESTOR
Fig. 20. Deduced phylogeny of the Mononchidae ( see text)
- 1+3 - immediate anccstral resembLd the moern liathyodon-
tidas more than any other group. sbra2 mononchi .-probably c- iffersd from L
Bathyodontidae in - ossessin eac:a e LE-1r
stomatal clerit This situt' comnon.
the Enoloi!.;.ea- end Iri -,-cduction the MaMbGT of, teeth apycars to rPth
primitive conCition in 1.7 1 -7 ha. elaboration
the oesophago-intestinal valve s.tract•_uos a ti rm of the s t oma appear to be later and strictly mononcbid develomasnts.
The 1-To-mononchid ancestral forlp. aTv 3ars to Aciw: I
rise to two distinct groups - presence of tubercla.; or non-tuberculat osso,:riazo-intestizial
junctions (Clerk, 1960 thi dic:.1Jtoy
is the sha)(- of the stores base is
in the tuberculate forms eri p intzei in the non-tuberculato
genera. 20). (The rare 01_ to this, lion Irrjoh4Es cra Cobb, and vorax Cobb, c ...a hm, :sic y not
ally b lone in the to have be
assigned, t no rial is available to k this i'liconczyus is placed rr.7._
line of development. This 7'nu., e.1.1 the appearances
of 15iL ClVC _lc.'s _.de stribution
A B
C Fig. 21. Anatonchus tridentatus (de Man). A and B larvae, showing the anteriorly directed tooth in A, and the posteriorly directed tooth in B. C. Adult showing the anterior position of the reversed teeth at this stage of the life history. - 101 -
(Europe, Africa, Austr, New e1end , Fiji, N orth South Americ). From hiconchiis 7 Axntonchu s readily derived by the rvc- t:te 'iyction of tba teeth rd the, acquisition on 011'6 oibsrior mg atir.iof the t,Ith. ers.nl of thz the tecth does in fact occur at tLn iirst xoult La
Aticlis t(9L.bus de lien, an(ft in bbis sae spec ies
the teeth move anteriorly at 2ac_., succe C. -77 racult (figs. 21 A.LC). R.H. pars, coliz.:) lies a paper in trie press uescriing bores ne Ilorth Aerican speci. s in this genus. if these are ta?eri into account
Anatonchus conta:Ine seven good siecie three '.2u2oen and four North American. An ai. hbh specia A. krcisc,i Mey1 is based on A. tridentatus o 2,3iS not de Man. The materiel on which t his spe iE:s is based consisted of one fsmalo and one juvenile. ,lreis aid not 6fs UFS the mor-eholoc:: of the juv,-,nilo which wita other snecies in the genus would be c7.-TscLed to differ in stomatc.1 characters from the eduLt e 11 Llib ecies is found a gain it would merit ti:1 ,,ction ;enus characterised by the presence of three reversed teeth S in Aqatonchus but wien the (iors1 tntri T:lacc, anteriorly to the subvcnbreIL ones.
lobonchas may also be deri.v(!_ from Miconchus by the - 45 - loss of _e subventral teeth. The tooth apex may occur
anywherebetween about 10 - ' the height of the stoma. calculated from the base. The oily records of this fairly large genus from Europe crc I. zscao (Menzel), I. bat2ties (Micol) and I. simmenensis (Kreis), all inadequately known species of which zgchok i and simmencnsis may be synonyms. The species of the' genus are distributed as follows Austria 1, Australia. 2, Brazil 4, East Indies 2, New Zealand 5, Switzerland 1, and U.S.A. 4. In all of the tuberculate genera the tail length garies considerably between species from 2% of the total length in Miconchus exilis (Cobb) to 43% in Iotonchus maragnus Clark.
Amongst the more numerous non-tuberculate genera the starting -ooint is similar in that Cobbonchus has a. stoma armed with three teeth; the subventral teeth may he much s-ca--dler than the dorsal one (C. chauliodus Clark) or about the same size (C. terres (Cobb)). From a Cobbonchus-like form the two closely allied genera Brachonchulus and MAilonchulus may be derived by reduction in the size of the subventrJ teeth and the app aranee of subventral denticles arranged in transverse rows. - 46 - Bra chonchulus is d_istinzuished from iloncbnlus by the presence of an additional 1.ostcrior patch of denticies. Graronchulus may bc derived from the main liiae either
before or after the emergence of :[\1omchols and 3rachonchulus. The main feature hec is the total
loss of the gubventral teeth, and the transverse rows of derticles uhich arc a conspicuous feature of Brachonolaulus and ilvlohchulus are r'K:duced- to a sAaPL,;, row and a ventral patch of irreg., _1Thrly ara'anF,ed danticles. Ja(,onchulus appears to be a smell side branch in which the dorsal
tooth moved into the posterior half of the stoma 9 and the subvcntro.l dehticls became reduced to a small patch, and the transverse rows of dnticles disappeared entirely.
SiDoronchulus on ths other hand appears to ha .ilueh closer to the main line of evolution and here there is , r!larked trend for the sup dnticles to become arranged into longitudinal rows. This is more obvious in species like S. soutoi (Carvalho) than in the type species. SporonchultIs appears to have given rise through ppra,]imatien of the rows of denticles into two medien ventral denticulate ridges to Prionchulus. The genus hononchus for the purposes of this discussion is best divided into wo groups; the "papillatus group" (aoill6bLls Ba,TJtian and 1-1:1221aLlilL12 Clark) which has a single low, non-denticulate ventral ridge and the truncates group containing the
remainder of th nus WhiCA have no such The former apv)ears to be more primitive in stomatal characters end the vontrel ridge is aT)parcntly derlved by fusion and reduction from the daubs ri of Pligichulus. In the
truncatus group the ventral ridge has disappeared entirely.
The fact that the genus kononchus falls into two distinct groups may be taken as evidence that the present distinction between the genera Prionchulus and Mononchus is unnecessarily arbitrary end it might be wiser to regard M. papillatus and M. lIopapilletus as members of the genus Prionchulus which would then include species with a ventral
ridge or ridges with or without denticuletions. Or, in order to preserve the homogeneity of the classification which is based primarily on stomatal characters the umpillatus" group of species -could be given generic status.
No formal change is propose. here.
In the non-tuberculate line of development from Cobbonchus to Si)oronchutus the tails are all short, often rather digitate, end usually less than 5%. of the total
length. In t genera Prionchulus and Mononchus caudal diversity makes its appearance, and the tails tend to be proportionately longer. - 48 The distribution of some genera is noteworthy; Sporonchulus is restricted to Brazil, Brachonchulus is known only from the East Indies (Sumatrn and Surinam) and Granonchulus and qudonchulus known only from Continental Europ3 and Florida. mononchus Prionchulus and Mylonchulus are cosmopolitan. - 49 - Section VII The superfamily DORYLAIMOIDEA 1. Descrijtion of Pungentus_ maorum n.sp. Family DORYLAIMIDAE Subfamily DORYLAIMINAE
Pungentus maorum n.sp. Figs. 22 A - G.
Holotype L. 1.64 mm; a = 31; b = 4.04; c = 57.3; V = 41.7 11 spear 32 p Paratypes (n = 24) L. = 1.645; (range 1.46 - 1.80), (s = ± 0.078mm); a = 34 - 42; b = 3.18 - 4.28; c = 50.3 - 56.1 Ir . 40.1 _ 45.5 10 - 18.
spear 30 - 35 ja
Tikipunga W (n = 24) L. = 1.61) mm (range 1.42 - 1.96 mm) (s = ± 0.107 m); a = 31 - 41; b = 3.51 - 14.56, c = 58.1 - 73.1; V = 40.0 45.1 10 - 18 spear 30 - 35p Porutawhao (n = 5) L. = 1.694 in (range 1.61 - 1.78) a = 38 - 41; b = 3.87 - 4.03; c = 68.4 - 70.1, V = 42.2 - 44.4 spear 32 - 33p
Males unknown. Cuticle 1 p thick with moderate transverse annulations. Subcuticle 1 p. thick in oesophageal region, but much thicker on tail where, it has a vertically laminated appearance as in
=NI
0 0
AE
B
D
Fig. 22. Pungentus maorum n. sp. A & B lateral and dorsal views of female hea:37 C oesophago-intestinal junction; D vulva in lateral view; E female tail; F en face view of lip region; G ventral view of vulva showing76Terite and slit in cuticle.
50 - Longidorus sap. o lateral fields. A ventro-medim series of fine cuticular pores similar to that described by GDodey (1943) is presuni. IL is best developed in the post-vulval region. Three caudal cuticulr pores present as shown in fig. 22.
Lip region offset, head reFjon tapers ant,eriorsy. Lips six, ,... ual, symmetrical; cephalic papillae in the
usual rings oi. and ten. The four small sole-rites about the month characteristic of thL. genus are arranged dorso- lateraUy and vantro-lota_ally as figured by Goodey for
P. thorp,ei, and not as figured by Thorne and Sanger 1936 for P. punens. Amphid apertures appear as crescentic slits in en face view, and r s bow-shaped lines in lateral vie-
Spear 30 - 34u long, length equal to two and a half times width of lip region, slightly arcuata. Spear extensions almost as long as spear. Extensions unite oesophageal lining in a distinct muscular bulb at the
anterior end of the oesophagus. Oesophagus dorylaimoid, expanded part equal to half of oesophagus length.
Oesophageal gland ducts occur 51-1-, 75 and 93 percent of oesophagus length. Osisophago-intstinal junction simple with a. moderately short, stout oesollthago-intestinal valv projecting into the intestinal lumen, hatestine simple,
passes dorsally to gonad. Prerectum indistinct, qual to - 51 - one end a half anal-body-widths in length. Rectum straight slender, almost equal to anal-body-width in length. Vulva. pre-equatorial, Vulva with four sclerotized plates, rather similar to those found in P. thornei but less angular centrally. The inner margins of the plates may be crenulata. The cuticle extends over the vulval sclorites, and makes the vulval aperture transverse and rather slit-like (fig. 20 G). Vagina extending across half body-width, very thick and solid. Anterior uterus represented by a short pr` -vulvel sac. Posterior uterus and oviduct outstretched; ovary singly reflexed through up to 85 percent of the total extent of the posterior reproductive structures. None of the specimens available (collected January - April) hod sperms in the reproductive tract, and only one female had an egg in the uterus. This measured 85 x 31p.. Tail short, length equal to 0.8 anal-body-widths, hemispherical in shape. Specific differentiation. Of the long speared s'ecies of Punsentus (those where the spear is about trice as long as the width of the lip regi.on, or longer) with a single ovary P. maorum n. sp. is distinguished from P. sparsus Thorne by the hemispherical tail, and from P. monohvstere Thorne and Swanger in having a more clearly offset lip region, an:. a proportionately longer spear. Differentiation fro,11 the - 52 -
unfigured P. ichthyuris (Cobb) is more difficult, but Cobb's species is smaller (0.86 um long) and apparently lacks the transverse annuletions on the cuticle. Type Slides. Holotype and partypes in the nematode collection, Entomology Division, D.S.I.R., Nelson, N.Z. Paratypes (slide Nos. 155/3/1-3) have also bean deposited in the slide collection, Nematology Department, Rothemsted Experimental Station, mc.en7 Herts., England. ype locality. Granity, N.Z.M.S.1. 23/24, 3118637 in rough pasture of Agrostis stolonifere L., Holcus lanatus
lqlpochoeris redicata L. end juncus sp. Soil a_ podzolic sandy loam. Other localities. Porutawhao, in Loliup perre L. - Trifolium re yens pasture, Soil Omanuke. peaty silt loam. Tikipunga in Pespalum diletatum Poir dominant pasture with Lotus hispidus Deaf., Plantao lanceolate. L., and Hypoc.:Loeris
radicata L. Soil; Hukerenui Silt Loam (a. podzolized yellow- brown earth).
2. Descrilption of Actinolaimus zealandicus n. so. Subfamily Actinelaiminae Actinol-,imas zealarZicus n.so. figs. 23 A - Holotypc L = 2.58 mm; a = 50; b = 2 56; c = 16.5;11+50.717 Spear 21 p. Allotype dl L = 2.65 mm; a. = 46; b = 4.6; c = 98, T = 27. sr,car 22,u For peratypcs see ta ble 1. D Fig. 23. Actinolaimus zealandicus n. sp. A lateral view of head; B en face view of head; C ditto at level of amphids; D oesophageal region; oesophago-intestinal junction; F ventral view of vulva; G optical section through vagina; H female tail; I male tail;) spicule. - 2i- Cubiclo 2 rd fi,Tie transverse
nr.ulations only visible unc.r oil i orsion Suhcuticle 2 r.
thick. Cuticuir porcs ent ,J rions 2 0 dorsal and v-m r1 -cair o hurt
,:ragdon offsot by rot constr4 cticn. Lip rcgion Laat on: third C2 7::ide ac,' body - t bo of oeso'phagus.
HLHd in vi circul r, with 11a3 in the innar ring t of lios. Withinha,
Loasr s of LI- _11 Is s,;en rotized annulu wny P ir r7,iatiaz ribs; spe,ar passes through tho control holc. At 0lowi3 level o focus 'cLi ton outer
p pillne q'e visib Laosa: of ,,rich lip arc sot in rather granular poster or to the annulus this r* ion is subdivided into poLrtions ':;hich- ar strikingly
lops of other ofloriluS Too latcral arc-; raLir irrgcr nor pointc,,d centri etally than aro
the aubmedian "1-Ws". Tia3 subs "lips" are not at all
point:4.1 Oil their inner Tho aohid apertures ap-coar
in this vilq larj,e cl- esce tic slit rro ng about the spoor &Kis aro four onclai, which in this vicw appear
as a cross 1tIa arm J.riang3 at h5 from the porcndiculor horizontal axes.
In lEltcral sclorotizeC o,hia extend from the anterior limit of ':,he nerd t he ant:rior fn.ce of the dcJbL3 guijng ring. Antiorly, processes arising from the - 54 - onchia support the annulus with raiCiatin ribs. Often the ,.:nnulus gives th3 u earance of being:; uoubi . 3pear strong
20 - 23 long; s, ear aperture Lwo-fifths of spear length. extension t,,..rmiratin2;- in j small swollen bulb of the oesoph-gas. TCITA tdon of r extension not clearly demarcated.
AI:d.ohids cup shaped; aperture ,..)out one third as
1g id'. head at this 0oint. Oesophagus 1,22:c.,a a. short muscular bulb about the base of the spear ext,7Jneions, then narrowing only to gradually wiper ain posteriorly, attaining intaini maximum and uniform ciameter in the posterior half. Nerve ring encircles the oesophagus at 29 percent of its length and the oesophageal gland ducts occur at 51, 76, and 88 percent. Ocsophago-intestinal valve variable in shape; conical, length usual half to three-quartrs of the maximum width of time ocsophagus. Intestine s simple tube passdorsally and to the right of both ovari2s and testes.
Pcmale. Vulva equatorial,. an elongateDo• (fig. 23F). Vagina with a cruciform lumen; 7-bonds across half of the
body width. Ovcri ircd, reflexed through their entire length, which is 7,qual to to two-thi of the
length of the oviduct and Co.71only it is terminal pert of the oviuct which is reflexed, so that 55 - strictly tha ovary is outstretched, but in le opposite direction to nital (:.u.ct . Prerectum 4 - 5 times the anal-bo(ay-uidth. Rectum slightly arcuate, on hd hzdf tir,,os the an&i-bod diameter. loll dor ly convex conr)id at first, then fililor, a pair Dnt, pair of lateral cuticular pores.
Eale. T estes paired oppOsGC.1 y outstretched. Testicular r. ang equal tc half length of v s dsfe:-ens. Vas aeferens constricted little giant- r—or the first supplement to form the ejacuI rto duct which may ,iiden near the middle of the ran of su, merits. Su,:,o1E'71.=, rts an ad anal pair plus - 18 ventro-median ones, (13 and. 15 are the most common nubers in the 'ct.ntm-median series).
The main series is c:)ntiguous and lies about one and half spiculo lengths nteri.or to the pair. S-J4cules
Paired, fre, heavy, arcur.te, min. median groove in the central prt. Spit.210 lengthequal to one quarter anal-loody-wiciths (55 aid chord). The lateral guiding -oi cos appear bifid at the. and somewhat rolled edstally. of 1''o le pr rectum variable h, commencing a little anterior to the six.Yclements or n the middle of the ventro-median scries of supplements, or between these two points. Toil short, length about threequarters of the are dor sa lly cone y Sot GWIIC t straightened - 56 -
vtntrally, tip rounded. Caudal clitico.lar pores as in fiwre 23 I. Larvae all have female tyl:e tails. Specific differertiation
Actinolaimus zealandicus n. sp. is distinguished from all other species in possessin a clearly offset lip reion, an almost smooth cuticir , amphid apertures one-third as wide as the head and locking dentil s in the stomatal region. The pore-like vulva may not be significant as this is not recorded in most descrilAions. Similar lack of information makes ono hesitate to place .:zuch weight of the form of the lateral guiding pieces in the male. A. zoalandicus is apparently rather similar to A. macrolaimus do Man and elabpratus Cobb, but differs in the absence of ribs in the stoma, and in the relative length of the spoor aperture. Holotype, allotype, and paratypss in the nematode collection, Entomology Division, D.S,I.R., Nelson N.Z. Paratyr2s (slide 1.59/4/1) also in slide collection, Nematology Department, Rothamsted Experimental Station, Har71enden, Herts. Enp;land. T'pe locality. Tutamoo, N.1, 1960725 570 n. liverworts and masses tame ikerith. (7.: Hook. f. pagadium ,qurTssAguIII Soland. forest. Other localities. Coliingwood, from leaf mould in aril ci - 57 Nikau Palm (Rhopalostylis side Wendl. & Drudo), Lake Maninapua Forest Reserve, from liverwort LeY)idocolea
scolopendra on Dacrydium cuyessini.lm Soland., and also from ocaLntinnia. acutifolia T. Kirk -- ;i2,ccApsa Linn. f. forest litter. Whangonos Hill in ?ittIsDc)rul-1 eugcroiodes A. Cunu. - flotiioanax CJnoi 3cem.
racemo, Hook.fil. fore st litter. Mt. Cook, Governors Bush in Hothofogus Msnzicsij Ocrst. Phvllopladus alLinus Hook. fil. Podosaruus HalliiT. Kirk forest litter. Mt. Messenger in Olen. Cunnin,,Yhamii Hook. fil. -. Vite: lucens T. Kirk - Shawin paniculota Worst. forest litter. Waitaanga Saddle from liverorts and mosses in Weinmannie racemosa Linn. f. Brechyglottis re-canda Forst.- tree fern forest. Hongi'q Track in Beilschmieqia. YEIW2 Brlth. & Hook. f. KnL7,7htin excelsa R. Br. - Pqdocayous Totare D. Don forest litter. Remarks. During moulting in tis species whole lining of the stoma, the spear and entensions tLethsi' with the guiding ring c,s tJell as the exo-cuticle is shed. xtricT:tion from the old cuticle apeors to be achieved by rupturing the old cuticle about tel head widths behind the
The measurements and do ken fo muLe of this species show cons•idere.ble variation, but tbere apper2rs to be only one species involved. Thorne (1939) noted similar vriations Table 1
Measurements of female Actinolaimus zealandicus n.sp.
Tutamoe Naitaanga Mt. Messenger Hongi's Track L. Mahinapua Hermitage Collingwood
n 4 3 6 2 3 2 1 L (mean) 2.65 1.83 2.52 - 2.58 - 2.83 range 2.58-2.70 1.78-1.9 2.13-2.75 1.78-2.08 2.38-2.84 2.88-3.03 - a 38 - 50 40 - 51 39 - 49 44 - 45 '49 - 51 47 50 b 4.4 - 4.56 3.4 - 4.44 3.6 - 4.57 3.78-3.88 3.92-4.39 4.38-4.4 4.52 c 16.5-23.9 10.8-19.3 11.5-16.3 11.3-14.6 14.4-16.7 18.8 18.5 a.o. 13 - 16 11 - 13 11 - 15 13 - 15 11 - 12 14 - 18 13 V 48.5-51 48.7-50.3 45.8-49.7 49.5-49.7 46.7-50.5 47.4-47.7 52 p.o. 12 - 17 8 - 16 10 - 18 8 - 15 13 - 14 14 - 15 14 Table 2
Measurements of male Actinolaimus zealandicus n.sp.
Tritan,ue Waitaanga Mt. Messenger Hongi's Track L. Mahinapua Hermitage Whangamoa 6 9 1,. 2 7 2 1
L (mean) 2.36 2.13 2.45 - 2.37 - 2.86 range 1.66-2.65 1.75-2.64 2.11-2.60 1.73 - 2.18 1.91-2.74 2.69-2.74 - a 45 - 56 45 - 54 41 - 55 45 - 49 42 - 53 50 - 55 52 b 3.61-4.6 3.52-4.71 3.92-4.44 3.5 - 3.95 3.44-4.52 4.35-4.37 4.31 c 69 - 107 70 - 109 78 - 95 62 - 90 79 - 94 85 - 109 87
T 24 - 34 26 - 37 25 - 42 33 - 34 23 - 32 24. - 29 35 - 58 - in the reported measurements of A. macroleimus de Man.
3. DescriaLion of Lonidorus taniwha n. sp. Subfamily Tylencholaiminae (including Longidorinaz) The Tylencholaiminae which now incorporates Thorners LongdJrinae (Chitwood, 1957) shares with the Diphtherophovoidea the rare distinction in the Enoplida, of including several plant parasitic species. The other agriculturally important feature of the biology of the group Concerns the ability of several species of Longidorus and Xiphinema to act as vectors for several strains of plant viruses which have polygonal shaped particles. Virus transmission by Trichodorus primitivus and T. Elchyderplus involves short rod-shaped virus particles (tobacco rattle virus).
Subfamily Tylencholaiminae Filipjev, 1934. Longidorus taniwha n. Figs. 24 A - I Barry town. 6 19 Holotype L.= 4.66 mm. a. = 54; b = 9.3; c = 151; V=1 51. spear 116 Allotype o" L. = 4.12 mm. a. = 53; b = 7.7; c = 134; T = 32 spear 112 p. Paratypes (n = 4) L. (mean) = 4.64 mm. range = 4.12 - 5.0mm; = 50-56; b = 7.79 - 9.72; c =149 - 163; V=16 - 20 49.5 - 53.8 10 - 19. spear 111 - 117 g . B
50A AB,H. 100P Ej. 200A
Fig. 24. Longidorus taniwha n. sp. A & B lateral and dorsal views of head; C en face view of hesid; D section through oesophagus; E female tail; F posterior branch of female reproductive system; G oesophageal region; H ventral view of vulva; I male tail.
-59- Runanga Pare type L. = 3.82 mm. = b = 7.15; c = 117; V= 10 4,11 Cuticle 3 p thick with obsolescent, very fine transverse striae. 3ubcLticlo 2 p. thick in cephalic region, but immensely thickened, and showing cross striations in the caudal region. The whole of the cuticle with well marked diagonal, somewhat anastomosing longitudinal striations which originate ente17-iorly on the dorsal and ventral mid- lines and converge posteriorly onto the "lateral field34. Lateral chord shows as a line anteriorly, but widens posteriorly, until posterior to the oesophagus it may be one as wide as the body. Cuticular pores of head region usually only two lethal
pairs 2 but a dorsal pore may be p ent. Usually only two pairs of cauaal cticular pores present on the female (fig. 24E), but occasionally a preanel pair is present. Cuticular caudal i)ois of male as in fig. 241. Lip region not ofset in lateral view, rather rounded. Papillae in two rings of six and ten each. Amphid apertures very obscure, appear as feint crescentic slits. Amphids large, bilobed, lobes roughly symmetrical and extend half way back to guiding ring; apparently connected posteriorly to sensillae at about the level of the spear guiding ring. These sensillac in turn appear to be obscurely connected to a pair of saccato structures lying about the middle of the oesophagus. In en face view the Ups - 6o - appear to be fused; the inner papillae are set on slight eminences and the outer ring arc lateral rather than apical in position. AmpAid apertures appe,?,r as small bi- crescentic slits. Spear 111 to 117 microns long, uniformly slender with a minute dorsal aperture; spear bflse flaring slightly at junction with spear extension. Spear extension sie asr, about half :s long as spear, Ythout knobs or other expansions except for a very s1 ight expansion at the posterior end. Guiding ring simple, united with the cuticular lining of the stoma. Nerve ring occurs at 38 percent of oesophageal length. No excretory pore seen., Oesophagus typical of the genusr anterior three- quarters very slender with the posterior quarter enlarged to form the "bulb". Slender part often looped anterior to bulb. Bulb apparently conLaihih6 the normal oesophageal glands whose ducts occur at 83, 90 and 98 percent of the oesophageal length (fig. 2+G) Oesophageal lining sclerotized, appears thick in lateral view, but in transverse section (fig. 24D) the thickening is seen to consist of six triangular scicrotized strands united by thin zones. The whole forms a thin tube, with a lumen of variable diameter. Oesophago-intestinal junction with a moderate but very variable oesophac-intestinal valve - 61 - ("cardia" of authors). Intestine wider then posterior part of oesophagus, a. simple tube, often with abundant oil droplets. Prerectam of female equal to seven anal-body- widths. Rectum stroieht, narrow, length equal to two anal- body-widths. Female. Vulva at 49 - 54 percent of body length, a. transverse slit, almost one-fifth es vide as body. Vagina extending across half the body width. Ovaries paired, opposed, singly reflexed through more than half the length of the oviduct and uterus, tapering towards tip and containing a number of o8cyt:s in e. single row. A conspicuous sphincter muscle is present et the oviduct- uterus junction. Egg 202 x 65,u. Male. Testes paired, opposed, outstretched; testes seven tenths as long as v2sdnItTens and ejaculatory guct. Intestine and vas deferens slightly constricted- opposite the fir:t and second supplements, and beyond this point become the prerectum and ejaculatory duct respectively. Supplements not pailloid, 15, not equidistant; the first 13 aro arranged alternately to the left and right of the ventral midline. The eaanal pair as usual. Spicules paired, free, arcuate, pointed tow.rds the tipes. Lateral guiding pieces pr3sent, but in the. only specimen available details of the tips ere obscured.
- 62 - Tail short, (length 7,13,2ut o e Ind n ho if anal-body- widths) rounded in fanals d htly .mosre pointod is the ti tioq n. sp. is rendily distiuished from other species in the genus by the regul7rly hcmishricol tnil _cid the .-0, !rly tapering, non-offset i In hand shn2e L. ta '5wha most closely
.1.)!:,roch- ,is L. goodei Hooper, (i n r ), but the tell is much morc rounded bnen in that species, and the arime1 is ensre smoller.
Holotypa, allotyps p,Irat.ipe slides a in nematode collection, Entomoloz Division, D.3.1.R., Nelson, N.Z. One pa type female (slide i o. 168/8/7) in slide collection, '_`Tema t.ology Deportment, itotLorasted Ex erimsntal St;:.tion, H.Irpenden, Aerts., EnEmd. Type loc it Johnson's Scenic Reserve, Barrytown N.Z.M.6.1. .37, 347223, etr2s, in rnemose. Linn. f. - tree-fern domin,:.ted forest . Soil; lkomtun sondy loom (an 177imF:turc podzolic soil). Other Runmga in very -wet lo_Lcus . tus L. kurostis tennis Sibtn. posture with jilc1)s ecer L. end Lotus Schlmnr. Remark. A moulting larva of this species (fig. 4A) proved interesting firstly for the light it s eds on the amount of cuticle cr,,st off r2t each ecd:;;isis, scon&ly for the - 63 information it gives on the spear. As ma,. be seen in the figure, the old spe the lin stoma, inclading tae guidirjg ring and the spear extension is shed. It may also
be noted that paft ofthe lining 1 the amphids is also shed. At theposterior end of ihie oesophagus, part of the oeso-onaeal lining was acting into the lumen of the intetine. Tdhether this is t7, be interpreted as an indication that the 1, or'terior part of the oesophageal lining is normally shed via. the elimenta caLlol at each moult, or merely as a fiation artefact is Dt clear. This specimen is also remarkable for its possession of three spears ) one being moulted, one moving into ,Frating position, and a third still lyin in the oesophagus
The specific epithet is Maori name for a legendary non-marine serFent.
A single female, apparently belong.ng to a further new species in this genus s found in the soil in a ,3atch of regenerating forest between Awatuna and Stafford. This species is cherecterised b3 the possession of emphids with extra-ordinarily lar a apertures, a spear of 21811, and a. tail which is absolutely a d 7(elatively longer than in L. taniwha. Head and tail shai)e ore rather similar. The Man formula, for this specimen is L. 617 mm; a = 47.5 b = 7.47 c = 73; V = 53. - --
+. Description of Sectonema taiaha n. sp. Family NYGOLAIMIDAE Subfamily Nygolaiminae
As discussed in section III I have somewhat changed the constitution of the family Holai :idas and made the fomi lJ more uniform in respect of spear type. All genera referred to it are characterised by the presence of a mural tooth, with, or without 9 sheath of spiral connective tissue about the enlarged part of the oesophagus. It may be noted that of the genera comprising this subfamily only Nygolaimus possesses the three "Cardiac glands" of Thorne at the oesophago-inteatinal junction. Thorne (1939) regarded them as a diagnostic feature. Thorne, 1930 has contributed all that is known of the biology of this group. He discussed the carnivorous habit of all the sTeci.7s he described, an.. stated that in his experience they were prede.cious upon enchytraeids (Oligochaeta), rat ter than upon nematodes. Sectomeha v ntralis was more voracious than any of the Nvolaimus spp. he examined. When attacking enohytraeids the tooth is everted anc the prey is slit by a dorsal to ventral slash of the tooth. In smaller Nygolaimus spp. (e.g. N. vl.liagaris Thorne) the fluid or granular contents are sucked out, but in larger speci s it appears from the copmon occurrence of enchytraeid setae in the intestine that the whole oligochaet 50 P 50)-1 IA,B,F
100 P 200P E
Fig. 2. Sectonema taiaha n. sp. A lateral view of head; B mural tooth; C female tail; D oesophageal regiorj; E posterior branch of reproductive tract; F mural tooth of Sectonema rotundicauda Goodey. b5 is devoured.
Sectonema taiaha n. sp. Figs. 25 A - E.
Holotype L = 5.37 mm; a = 29; b = 4.11; c = 100 V9 40 13 tooth blade (tip to shoulder) 18f Cuticle 3 p. thick with very faint obsolescent transverse striae; subcuticle 2 p thick (measurements taken at posterior end of oesophagus). Cuticles much thicker just behind lip region. Lateral chords very narrow anteriorly, one-sixth as wide as the body in the middle region. Cephalic cuticular pores four dorsal and four ventral; a. lateral series is also present. Caudal cuticular pores represented by two post-anal pairs. (fig. 25C) Lip region clearly of t, lips distinct, rounded; papillae in two rings of six and ten each. Amphids stirrup-shaped; half as wide as head at this point. Amphid apertures appear as bow-shaped slits in lateral view. Stoma with a broad eversible vestibule on whose left ventro-submedia.n la.11 is attached a large mural tooth. Tooth complex, consisting of a slender rod posteriorly (= spear base ?) which at the level of the third ventral cuticular pore is distinctly marked off from a more posterior part (= spear extension ?). Anteriorly the spear base swells and forms a solid. rounded base for the tooth from - 66 -
which arises a thin, pointed blade with a thickened rib along the ventral edge. Oesophagus long, gradually wiening through the anterior third, and thereafter remaining about half as wide as the body. Nerve ring encircles the oesophagus at 18 percent of its length. Dorsal oesophageal gland duct occurs at 34 percent of the oesophageal length and the anterior subventral gland duct at 72 percent. Posterior subventral gland duct not seen. The "cardiac glands" of Thorne are not present at the oesophago-intestinal junction. A slender pointed oesophago-intestinal valve projects into the lumen of the intestine. Intestine a simple tube which passes to the left of the anterior ovary and to the right of the posterior one. Reproductive structures paired, ovaries singly. reflexed through half to one-third of the length of the oviduct and uterus. Vagina. thick-walled, extending across half the body width. Ovum length equal to twice body width. Length of prarectum almost equal to four anal-body- widths. Rectum straight, length equal to one anal body width. Tail short, rounded, length equal to two-thirds of anal body width. Specific differentiation. S. taiaha, is readily distinguished from S. ventralis Thorne by the more rounded tail and the - 67 -
paucity of the caudal cuticular pores. It differs from S. rotundicauda Goodey (known only from a single male) in the shape of the spear (c.f.figs 25 B & F). Goodey ,s species has a. single caudal pore. Type slides. Holotype in nematode collection, Entomology Division, D.S.I.R., N.Z.
Type locality. Westport pakihi, N.Z.M.S.1.1 085674 in pakihi vegetation (Geicl:ipnip circinate Schwartz, stunted Lebtospermum scoparium Forst., Drof,ra sr)athulatA Labill., Thelymitra spp.) Soilg Gorge fine sandy loam (a podzolic soil). Remarks. The specific epithet is the Maori name for a short, broad-based spear-like weapon used in hand-to-hand fighting.
5. Description of Dorlaimellus monticolus n. sp. Family BELOITDIRIDAE This family appears to be well represented in New Zealand :Nils; the genera Belondira Thorne, Axonchium Cobb, and Dorylaimellus Cobb have all been recognised. Dorylaimellus is especially abundant, being represented by at least four species in the sample from which D. monticolus n. sp. is described, and a further five or six species from other localities await description.
B
► 25P IABDEF
X SOP 1G
G
Fig. 26. Dorylaimellus monticolus n. sp. A dorsal view of head region, B lateral view of head to show amphid, C en face view of head, D oesophago-intestinaL junction, E ventral view of vulva, F female tail, G oesophageal region. - 68 -
Dorvlaimellus monticolus n. sp. Figs. 26 A - C Holotype L = 0.76 ram; a = 34; b = 3.06., c = 32; V = 8 641°
Paraty e W (n = 2) L # C.74 - 0.77mm; a = 32 - 35 55_588-10 b = 2.88 - 3.18; c = 24.9 - 32.0; v =7-8 Cuticle smooth, aubcuticle with well marked annulations; cuticles 1 ju thick. Lateral chords conspicuous in some specimens, but not in others. No cuticular pores seen on any part of the body. Lip region offset by a marled constriction which is reinforced. by the very large amphies. In en face ;view lip region hexagonal, lips equal, outer edge of each lip rounded.
A- Cephalic papillae in the usual rin7s of six and ten, the outer ring being lateral in position. In lateral view the lip region is bi-convex and the outer ring of papillae are more easily seen in this view than in en face. Four small sclerotized plates arranged as in figure 26 are clearly visible near the anterior limit of the stoma. Amphids pocket-shaped, apertures almost encircling the heed. Posteriorly the amphids communicate with sensillae. S-Qear 7.5p long , dorylaimoid; spear extensions of two re gions, a short tube-like anterior part and a larger posterior part consisting of three solid radiating flanges. Extensions one and a quarter times as - 6) - long as spear. Oesophagus expanding to form a small bulb just behind the flanged spear extensions, than narrowing again, and continuing as a narrow tube to 40 percent of its length where it expands to form the large broad posterior part. Posterior part of oesophagus with a spirally marked sheath. Ocsophago-intestinal valve broad or conoid uith a rounded tip. The lumen of the oesophagus is apparently without any greatly thickened lining, and through the greater part of the oesophagus the lumen is not visible. No sclerotized lining of the lumen was detected in hand-cut transverse sections of the oesophageal bulb. Dorsal oesothageal gland duct near the anterior limit of the broad posterior region of the ocsophap:us. Subventral glands or their ducts not seen. Nerve rina encircles oesophagus near the middle of the narrow region'. Intestine composed of small cells with dark granular contents. Intestine passes t..2 the left of the anterior ovary, and to the right of the posterior one. Prerectum three and'a half times the anal-body-width. Rectum slightly arcuate, length equal to three-quarters of anal-body-width. Vulva. siihtly :post-equatorial, and is situated at the bottom of a. shallow, circular depression. Vulval aperture a short longitudinal slit. Vagina short; uteri and oviducts paired, opposed, outstretched; ovaries reflexed - 70 - through three-fifths of the distance back to the vulva. Tail moderately short, length. equal to twice anal-body- width; dorsally convex, ventral side almost straight, tail tip sub-di,-itate, rounded. Specific differentiation. D. monticolus n. is similar to D. striatuA Thorne, 1939 which is stated to .tave transverse striae on the cuticle, but differs markedly from it in tail shape. It also beers a superficial resembrlance to the much largerD. v ir; Cobb, but D. monticolus has a shorter digitate caudal region; further, the shape of the anterior oesopha, eel bulb and the oesophago-intestinal valve differ in both species. Type slides. Holotype and pare ty slides in nematode collection, Entomology Division, D.S.I.R., PTelson, N.Z. Type locality. Summit of Lindis Pass, Y.Z., 1000 metres in a. skeletal yellow brown earth. Vegetations Danthonia flavescens Hook. f. Foe. Colensoi Hook.f.sub-alpine grass- land with Cclmisia fracilenta Hook. I., .Laugopoaon fraseri
A. Gunn., Reoulia Hook.f. app. and Festuca novaezelandeae Cockeyne.
6. Description of AmpLorostomum saccetum n. ,gen.et sn. Family LEFT6NCH1DAE As mentioned earlier- (Section III) the Leptoncnidae do not form a. very coherent group. The addition of the genus described below doe not affect this situ tion in any - 71 - way. Whilst no other genus in the family contains species with sclerotizations A-Jout the :stoma, this does not appear to be e character of more than ,eneric significance. Stomatal sclerotizations occur in Punentus in the Dorylaiminee, in varying degrees in all the Actinolaiminee and in Dorvlaimellus in the Belondiridae.
Amphorostomum n. g. Leptonchidae; moderate sized nematodes, with a flask- shaped sclerotized stomatal lining extending posteriorly to the anterior limit of the spear guiding ring and through which the spear runs. Amphids large with sinuous apertures. Oesophagus very slender in anterior three-quarters; basal bulb short, marked off by e distinct constriction. In the only known species only the anterior ovary is present, posterior genital tract forms a. 1,?rge post-vulval sac. Males tastes dorylaimoid; spicules heavy, arcuc,te, paired, free. Lateral guiding pieces present. Supplements, an adanal pair plus five ventro-median ones. Tail similar in both sexes, short, rounded, with a terminal invagination of tail hypodermis.
Type ST2,6CieS; Amphorostomum sa.cca.tum n. sp. Remarks. On the basis of the offset, short posterior oesophageal bulb Amphorostomum appears to lie close to Doryllium Cobb and Tyleneholaimellus Cobb, but differs from both these genera. in the possession of a very slender, - 72 - uniformly tapering spear with simple extensions which lack both knobs and flanges. The most important single character is the possession of a flask-shaped sclerotized lining to the stoma. The name is derived from emphoreus = a flask, and stoma. = a mouth. Amphorostomum saccatum n. sp. Figs. 27 A G Holotype * L = 1.56 mm; a = 32; b = 6.21; c = 96.5; V 17 52 13.5 Allotype o L = 1.65 mm; a. = 34; b = 6.8 c = 85.5; T = 38 Paratype L = 1.68 mm; a = b = 7.06; c = 96; V=1554 13.5 Paratype o L = 1.67 mm; a = 35; b = 6.37; c = 69; T = 35 Cuticle 1.5 u thick with an abundance of irregularly placed raised dots visible under oil immersion. Sub fig. 27C. cuticle 1.5 u thick, with fins transverse annulations. Lip region in en face view rather hexagonal, lips equal, inner ring of 6 papillae within the lip region; outer ring of ten papillae placed on the sides of the lips, and appear outside the lip region (fig. c). Amphid apertures large, slit-like, but somewhat dilated at each end. =t lower levels of focus the sclerotized lining of the stoma is seen in optical section as a. complete ring. In lateral view the lip region appears slightly offset. Amphid apertures somewhat bi-crescentic in this view, and are easily confused with the depression which offsets the Ui
ABD EF
Fig. 27. Amphorostomum saccatum n. gen. et sp. A & B dorsal and lateral views of head; C en face view of head; D female tail; E oesophageal region; F male tail; G female reproductive system. - 73 - lip region. Amphids pocket-like, connecting posteriorly with sansillao. Stoma lined in the posterior half with a flask-shaped sclerotized lining which is cylindrical in the posterior third, and inflated the centre of the anterior two-thirds, and neerows anteriorly and posteriorly from this point. Spear 9.5 u long, slander, paring uniformly to a fine tip. Spear aperture not seen. Extensions simple, without flanges etc., about equal to spear in length, posterior part in a. slight expansion of the anterior end of the oesophagus. Anterior three-quarters of oesophagus long end slender; osterior quarter half as wide aas the body and sharply offset from the anterior part by a marked constriction. All oesophageal gland ducts discharge into the oesophageal lumen in the expanded posterior part. Nerve ring encircles the oesophagus slightly anterior to the mid-7,Doint. Oesophago-intestinal valve rather short, posterior part broad. Intestine a. simple tube passing dorsally to the male and female reproductive organs. No distinct prerectum—• in female. Prerectum in male commences near the most anterior supplement.
Female. Vulva almost equatorial; a transverse slit. Vagina extending across half the body width. Posterior uterus present as a large post vulval sac filled with sperms - 74 - in both females, with a small cellular body (= the reduced ovary ?) attached to the distal extremity. Anterior uterus outstretched, but the oviduct reflexed a short distance from the tip. Ovary and. terminal part of oviduct reflexed half-way back to the vulva. Tail short, length equal to two-thirds of anal-body-width, rounded. No caudal cuticular pores seen. Male. Testes paired, outstretched. Vas deferens expanding a little anterior to the first supplement to form the ejaculatory duct. Supplements en adanal pair plus five ventro-median ones, all low, mammiform. Spicules paired, equal, free, heavy, arcuate. Lateral guiding pieces present, slightly arcuate, tips rounded. Male tail short, length eglal to three-quarters of anal-body-width, tip rounded. No caudal cuticalar pores seen. Type slides Holotype, allotype and pare types in nematode collection, Entomology Division, D.S.I.R., Nelson, N.Z. Type locality. Westport Pakihi, N.Z.M.S.1., 085674, in soil with Gleichenia circinate Swartz, stunted Leptospermum scoparium Forst., and Drosera L., Thelymitra Forst. and Ceimisia Cass. spp.. SoiL Gorge fine sandy loam (a gley podzol).
Remarks. The specimens examined were apparently preparing for the breeding season since both the females had abundant spermatozoa in their post-vulval sacs. No eggs were - 75 - present (material collected in February). The specific name draws attention to the enormous post-vulval sac. In some respects Amphorostomum saccatum a..-)pc=s to be allied to Tylencholaimus brvophilus Imamure, 1931. The similarity in the shape of the oesophagus is vary striking, end apart from the presence of caudal pores the tails are somewhat similar. The exact nature of the stoma is not clear from the figures and not discussed in the text. Significant points of difference concern. the spear which is stated to be trifurcated at the base, though no spear extensions are shown or mentioned. The adanal supplement is referred to in the singular and the prerectum is stated to be halways distinct". I do not feel justified in regarding all these differences as due to "faulty interpretation" as has happened so frequently in nematology. It appears unlikely from Imamura. (1931) that type specimens were kept, so it is probably as well to wait until further information is available about this ecies before rerroving it again from the genus to which it Was first assigned. - 76 - Section VIII
CONCLUSION
So far as any general remarks can be made about the free-living nematode fauna of New Zealand at this stage it alnars to charactris d by a very high degree of endemism. The endemic status of many of the species can only be tentative at present because virtually nothing is known of the nematode faunas of the adjacent land masses of Australia, Tasmania, the Pacific or Sub-antarctic Islands, or even of Chile. If, however one extrapolates from what is known of the rest of New Zealand's fauna a high degree of ondemism is to be exnected. This is no doubt due to a high degree of isolation from other land masses simo Cretaceous times. On the other hand, it is to be expected that wh-2n the faunas of arable land are studied it will be found that many European species have become ;,:sablished as is the case in the other terrestrial invertebrate groups, e.g., Insecta, Arachnida, Crustacea, Myriapoda, Oligochacta and Mollusca. At the present time it is clear that amongst the Enonlida very many species, a number of genera, and a family or two require description. Although the Tylenchida and Chromodorida have only been studied in a most cursory fashion it is evident tht several new genera at least are required in these groups to accommodate as yet undescribed -77- species.
It is far too early in the study of the hew Zealand fauna to consider inter-rlationships between soil, vegeta- tion and nematodes, .;xcrept as nimtion d oarlior that most of thc,- Iotonchus seem to be associated with podzolic soils. Besides the erection of n,•-w so cies, this study of a few repr:_:sintatives of a single order of nematodes has served to show deficiences in some of the currently accented con- conts in the taxonomy of the group. Attempts have been made to remedy these as far as Tlossible but a considerable number of new problems hve arisen. come of these which are of more general interest and which require further study are:- 1. Re-examination of the number of oesophageal gland cells, and the nositions of their ducts in g1a1L=LLWI.Li_ the Diuhtheronhoroidoa and Alaimoidea. 2. The extent of moulting in the Dorylimoidea, i.o., is the whole of the ocsophagoal lining shed in all groups, and is this ever shed via the intestine.
3. The physiology of ieoulting in the Nematoda as a whole and a comoarison with similar phenomena in the Arthropoda. 4. The nature of the tooth in the Batbyodontidae and its mode of origin at tech moult. 5. A comparison of the formation and migration of teeth and socars in Ironus and the Dorylaimoidoa. - 78 - 6. Spermatogensis in the Enoplida with special reference to the Alaimoidea. 7. The nature of the spiral sheath in the Belondiridac. 8. The normal food. habits of all groups. - 79 - APPENDIX I A List of Eno,plid Genera recoenised in Soil Sam-Iles from Nsw Zealend
Oncholairpus Dujardin, 1845 Ironus Bastian, 1865 Crviotonchus Cobb, 1913 Trilpyla BDstian, 1865 Tobrilus Andrassy, 1959 (sysral sob.) new genus near Tobrilus Alaimus de Man, 1880 Arnhidelus Thorn, 1939 (6 or 7 spi).) ? new genus near Amohidelus Mononchus Bastian, 1865 (4 spn.) Prionchulus (Cobb, 1916), CAitw. & 01:dtw. 1937 Mylonchulus (Cobb, 1916) Pnnak, 1953. (2.srao. Cobbonchus Andrassy, 1958 (3 or 4 sm) Iotonchus (Cobb, 1916) AlthErr, 1950 (6 or 7 snp.) Labronema Thorne 1939 Aborcelaimus Thorne and awanger, 1936 (many sp-o.) Dorylaimus Dujardin, 1845 (several s-,T)o.) Eudorylaimus Andrassy, 1960 (several s-op.) Mesodorylaimus Andrassy, 1960 Discolaimus Cobb, 1913 Pungentus Thorne & Swanger, 1936 Tylencholaimus de Man, 1875. (several s,)7.) — 80 - Enchodclus Thorne, 1939 (sovral sops) Actinolairms Cobb, 1913 Nygo1airus Cobb. 1913 (sevr1 sT)o.) Sctonria Thorn, 1930
Loligljorus Micol. 1922 (2 spp.)
? Morn, 1939 Bolondira 1hornL, 1939 (s\R3ral s-)0.) now gnus riar londira (2 or 3 sop,)
AxonchiL Cobb, 1920
Dorylat1211us Cobb, 1913 (n3any so.)
Thorn bwang 1936 ? Doryiliunl Cobb, 1920
TvlincholTtimllus Cobb, 1920 s:.vral spp.) n2;14r gnus and far:lily or subfAily btwean Lc-ptonchidae
11-1(2 i71Aricholinaa now gnu nar Ty*:ipLus- Thorn, 1939 Amphorostouum n. g,)n0
consid,ft7tbiw v:Lrity of liotonchid s--)p. which flood furthor sLucly to •letssIrr_ino gincric osition. ',71-rior,:,:rmis sp. - 81 - REFERENCES
Allgen, C. 1933. Uber eini frei lebende Nomatoden aus dim Niederkongo. Zool. Anz. 20, 312 - 320. Altherr, E. 1950. Les nematodes do Piro National Suisse. Ergebn. wiss, Unt0rs. schwiez Nat. Parks 34 1 -46. 1960. Results from the Danish Expedition to the French Cameroons (1949 - 1950) XXVIII - Nematodes limnicoles. Bull. Inst. franc. noire, 22 33f. A. 770 - 787. /indr-ssy, I. 1956. Susswasser-N-matodon 'flas Fransbsich- Wesc-Afrikq. Oousc. tool. Univ. Bn., 1, 3 - 18. 1958. Ubor der System dor Mononchiden (Mononchidee Chitwood, 1937; Neulatoda). Ann. Hist.-rmt. Mus. hung., n.s. 24 151-174. Baker, A.D. 1953. Ranid method for mounting nematodes in glycerine. C'Inad. Ent. Lo 77 - 78. Canning, E.U. 1961. Legerella helminthorum n.s13.1 a coccidian parasitic in a nematode. Arch Protistk. (in ,Dress)
Chitwood, B.G. 1957. A new soecies of XiDhinemella Loos, 1950 (Nematode) from Florida. Proc. Helm. Soc. Wrsh., 24, 53 - 56. chitwood, B.G. & Chitwood, N.B. 1937. The histology of n_mic ocso'thagi VIII. The oeso-ohgus of rcpresentatives of the Enoolida. J. -Wash. Acad. Sci. L., 517 - 531. 1937. An Introduction to Nenatology, Section I, Part I. Chitwood, Monumental Printing Co. Baltimore. op. 1 - 53.
1938. ibid, Section I, Part II. Chitwood, Monumental Printing Co. Baltimore, -op. 55-123. 1940. ibid. Section I, Part III & section II, Part I. Chitwood, Monumental Printing Co. Baltimore, on. 125 - 242. An Introduction, to Nematology, Part I (second edition) Chitwood, Baltimore, 213 op. - 82 - Clark, W.C. 1960. The o,:sooh,, go-intestinal junction in the Mononchidac (Eno)lida, N,matoda). Nemtoloica, 5, 178 - 183. Cobb, N.A. 1893. Nematodes, mostly Australian and Fijian. Macleay Memorial Volume. Linn. Soc. N.S.W., 1 - 59. 1913. nematode genera found inhabiting fresh water and non-brackish soils. J. Wash. Acad. cci. 1, 432 - 444. 1916. Notes on new genera and SIDOCies of nematodes 4. "Subdivisions of Yononchus." J. Parasit., 2, 195 - 196. 1917. The Mononchs (Mononchus Bastian, 1865), a genus of free-living predatory nematodes. Coil Cci., 431 - 4466 1918. Filter-bad nemas: Nematodes of the slow sand filter beds of American cities (Including new genera and soecies.) With notes on hermaphroditism and parthenogenesis. Contrib. Sci. Nematol. (7) 189 - 212. 1922. A new so&cies of Nvg:olaimus, an out- standing genus of the Dorylaimidae. J. Wash. Acad. Sci. 12, 416 - 421.
1928. Nemaic Spermatogenesis, with a suggested discussion _of simple organisms, -- Litobionts. J. Wash. Aced. dci. 18, 375 - 387. de Conninck, L.A.?. 1939. Les nematodes libres de la grotto de Han :Han-sur-Lessa, Belgique). Note de biosoeleologie. Bull, Mus. Roy. Hist. Nat. Belg., 15, 1 - 40. Ditlevsen, H. A. 1911. Danish free-living nematodes. Vidensk. Nedd. ihnsk naturhist. For. Kbh. Ll, 213 - 256. Forster, R.R. 1954. The New Zealand_Harvestmen (suborder Laniatores), Canterbury L. N. Z./ Mus. Bull. 2. 329 PP. 00 Filiojev, I.N. 1936. Uber Cryptonchus Cobb, 1913; Miscellania Nematologica III. Zool. Anz. 114, 105 - 106.
- 83 - Goodey, J.B. 1957. Laboratory Methods for work with plant and soil nematodes. Tech. Bull. 2, Min. Asric. Fish. & Food. H.M.S.°. London. 47 pp. 1961. The Ni cure of the spear guiding aplaratus in Doryl , imidae. J. Helm. (in Dress) Goodey, T. 1943. On. Pum"?ontus thorn_i n. sp., a new dorylspimid n_matode from soil. J. Helm., 20, 6 - 9. 1951. Soil and Freshwater Nematodes. London, Methuen. 390 pp. Hooper, D.J. 1961. A redescrintion of Longidorus olongatus (de Man, 1876) Thorne & Swanger, 19367 (Nematoda, Doryleimidee) and descriptions of five new SDOCiS of Longidorus from Great Britain, Nematologica, 6 (in Dress). Imamura, S. 1931. Nematodes in the paddy field, with notes on their populations before and after irrigation. J. Coll. Agric. 198 - 240. Lee, K. E. 1959. The earthworm fauna of New Zealand. Bull. N.Z. Den. sci. industr. ryas. 130, 486 pp. de Man, J.G. _1884. Die frei in dor reinen Erde und in sussen Wasser lobenden Nematoden der niedorlandis- chen Fauna. Eine systematische-faunistische Monographic. Brills, Leiden 206 op. Meyl, A.H. L71960_7 Die Tierwelt Mittclouropas Bd.l. lief 5a, Freilehonde nematodon. Quell° & Meyer, Leipzig, I op. + 54 pls. Micoletzky, H. 1921 & 1922. Die, freilebenden Li-cl-Nematoden mit besonderer BcrUcksichtigung der Steirmark und der Bukowina, zugloich mit c.iner Revision samtlichor nicht mariner, freilebonder Nematoden in Form von Genus Beschreibungen und Bestimmungs- schlAsseln. Arch, Nature. Berlin, Ilbt. A. L. 1 - 320, 321 - 650. 1925. Die freilobonden Stisswasssr- und Moor- Nematoden Dinomarks. K. densk vidensk. Selsk., .pfd. 8, 10, 57 - 310. - 84 - Oostenbrink, M. 1960. Estimating nematode iooulations by some selected methods. Pp 55 - 102 of Nematoloao fundmentals and recent advances with emphasis on plant parasitic and soil forms edit. J.N. Sasser and W. R. Jenkins. Univ. of North Carolina Press, Chapel Hell, 480 op.
Overgaard Nilsen, C. 1949. Studies of the Soil Microfauna II. The soil inhabiting nematodes, Natura Jutlandica, 2, 1 - 131. Owen, G. & Steedman, H. F. 1956. Preservation of animal tissues, with a note on staining solutions. Quart. J. micr. dci. 97, 319 - 321. Schnieder, W. 1922. Freilebende nsswasser Nematoden aus ostholsteinischon Seen. Nebst Bemerkungen 'uber die Nematodenfauna des Madu- and Schaalsees. Arch. Hydrobiol. La, 696 - 753. Schuurmans Stekhovsn, J.H. 1951. Nematodes saprozoaires et librJs du Congo Beige. Mem. Inst. Sci. nat. Bolg., 2, 1 - 79. Steiner, G. & Heinly, H. 1922. The possibility of control of Heterodera radicicola and other -)lant- injurious nemas by means of predatory nemas, especially by Mononchus paoillatus Bastian. J. Wash. Ac Pd, Sci. 12, 367 - 386. Taylor, N. H. 1948. Soil Map of New Zealand. Soil Bureau, Wellington.
& Cox, J.E. 1956. The soil pattern of New Zealand. N.Z. Inst. Agric. Sci. Proc. 1956, 28 - 44. Thorne, G. 1927. The life history, habits, and economic importance of some mononchs. J. Agric. Res. "-4, 265 - 286.
1930. Pr dacious nemas of the genus Nygolaimus and. a new genus Sectonema. J. A ric. Res. (Wash.), L22.1 755 - 763. 1939. A monograph of the nematodes of the suoerfamily Dorylaimoidea. Capita Zoologica, 8, 1 - 261. 85-
& wangor, H. 1936. A monegra-)h of the naaatodo genera Dorylaimus Dujardin, ADorcelaimus n- g., Dorvlaimoides n. g., and Pum7entus n. g., Capita Zoologica, 6, 1 - 233. Wieser , W. 1953. Ru-ports of tho Lund University Chile Ex-)Aition 1948 - 49.10 Free-living Marine NematoOms. 1, Enoploidaa, _'lc to Univ. lund. n. e. 49, (6) 1 - 155. 6. The Mononchidae (Enoplida, Nematoda) of New Zealand. II. The genus Iotonchus (Cobb, 1916) Altherr, 1950. Nematoiogica 5 (1960): 260-274. Leiden, E .J. Brill
THE MONONCHIDAE (ENOPLIDA, NEMATODA) OF NEW ZEALAND II. THE GENUS 10TONCHUS (COBB, 1916) ALTHERR, 1950
BY
W. C. CLARK Rothamsted Experimental Station, Harpenden, Herts, England 1)
COBB ( 1916) first erected /otonchus as a subgenus of Mononchus Bastian, 1865 for large species with a small basal tooth or teeth, an elongated, three-ribbed stoma, a long slender tail, and single or paired reflexed ovaries and he designated M. gymnolaimus Cobb as the type species. ALTHERR (1950) and PENNAK (1953 ) first gave lotonchus generic rank. Apparently unaware of this, ANDRASSY (1958) did the same, but placed the forms with subventral teeth in a new genus Micon- chus. It is not possible to separate some species (e.g. I. parazschokkei (Allgen)) from Mononchus using the generic definitions of Cons (1916, 1917) or AN- DRASSY (1958). In some species the dorsal tooth may lie partly in the anterior and partly in the posterior half of the stoma. The position of the tooth apex is net fixed and ranges over about ten per cent of the stoma length in most species. With the possible exception of I. zschokkei (Menzel) the stoma base is broad in lotonchus and pointed in Mononchus. The different types of oesophago-intestinal junction in the two genera (CLARK, 1960) simplifies generic determination.
lotonchus (Cobb, 1916) Altherr, 1950. Emend.
Mononchidae. Stoma large, barrel-shaped, with a broad base. Dorsal tooth ante- riorly directed, moderate to small, often basal, but always within the posterior two thirds of stoma. Subventral teeth or denticles absent. Oesophago-intestinal junction tuberculate. Ovaries paired or single, reflexed. Testes paired opposed, outstretched. Spicules paired, free. Gubernaculum simple or with lateral processes. Lateral accessory pieces present or absent. Tail short, conoid, or long, conoid with with a cylindroid end piece or filiform. Tail in both sexes similar or different. Found in soil, mosses, liverworts, and forest litter. Type species .Mononchus gymnolairnus Cobb, 1893.
1) At present on study leave from Entomology Division, D.S.I.R., Nelson, New Zealand. MONONCHIDAE OF NEW ZEALAND II 261
The known species of Iotonchus are: I. acutus (Cobb, 1917) Andrassy, 1958 1. oPhiocercas n. sp. I. amphigonicus (Thorne, 1924) Andrassy, 1. parazschokkei (Aligen, 1929) Andrassy, 1958 1958 I. basidontus n. sp. I. percivali n. sp. I. bathybius (Micoletzky, 1913) Andrassy, I. piracicabae (Lordello, 1953) Andrassy, 1958 1958 I. risoceiae (Carvalho, 1955) Andrassy, 1958 I. brachylain2us (Cobb, 1917) Andrassy, 1958 I. .rimilis (Cobb, 1893) Andrassy, 1958 I. consimilis (Cobb, 1917) Andrassy, 1958 I. sitnmenensis (Kreis, 1924) Andrassy, 1958 I. gymnolaimus (Cobb, 1893) Andrassy, 1958 1. tenuicaudatus (Kreis, 1924) n. comb. I. jairi (Lordello, 1958) n. comb. 1. frit-hums (Cobb, 1917) Andrassy, 1958 I. maragnus n. sp. 1. zschokkei (Menzel, 1913) Andrassy, 1958
lotonchus basidontus n. sp. Figs. 1A-G Ross Holotype ? L = 1.81 mm; a = 30; b = 3.67; c = 6.82; V = 9 59.8 7 Allotype 6 L = 1.95 mm; a = 30; b = 3.85; c = 8.60; T = 19.5 Paratype ? L = 1.68 mm; a = 32; b = 3.76; c =.7.16; V = 7 58.1 8 Awatuna-Stafford y L = 1.82 mm; a --- 28; b = 3.82; c = 6.85; V = 8 56.4 7 Awatuna. y L = 2.44 mm; a = 25; b = 4.32; c = 6.85; V = 11 55.2 is Hongi's Track Y (n = 2) L = 1.91-1.95 mm; a = 31; b = 4.03-4.08; c = 6.45-6.66; V = 8-9 58.1-59.7 7-8 Cuticle 2 p. thick, with very faint obsolescent striae. No lateral fields. Sub- cuticle 3 p. thick, not striated. Head narrowing anteriorly, lip region scarcely offset. Lips and papillae not prominent in lateral view. Amphid situated one half head-width behind lateral lip, aperture oval. In en face view lip region is hexa- gonal, symmetrical; lips six, equal, inner edges rounded, outer edges angular. Papillae in two rings, inner one with six, outer with ring of ten papillae. Amphid apertures crescentic in this view. In lateral view stoma is barrel-shaped, width five-eighths of the height, base broad, somewhat rounded, anterior portion not greatly in-arched. Anterior aperture half as wide as the greatest width. Dorsal tooth low, at 75 per cent of the length of the stoma, and occurring on posterior limit of anterior dorsal element. Tooth apex sharp; anterior edge of tooth concave; posterior edge straight. Apart from the presence of the tooth, dorsal and sub- ventral anterior stoma elements similar. Postero-dorsal element thicker than sub- ventral members, but thins towards oesophageal lumen. Suture between anterior and posterior elements clearly marked. Anterior four-fifths of stoma within a thin muscular sheath; posterior fifth embedded in locally enlarged anterior end of oeso- phagus. Oesophagus narrows a little to nerve ring at one-third of its length, then increases slightly to occupy half the body-width. Dorsal oesophageal gland duct at half the oesophagus length; subventral glands discharge into posterior third of oesophagus. Oesophago-intestinal junction tuberculate (Fig. 1 C). Intestine with abundant oil droplets and dark granules.
Female Vulva transverse; vagina thick walled, extending across one-third of
262 W. C. CLARK body. Uteri and oviducts outstretched, a sphincter muscle present between uteri and oviducts, but the glandular region, observed in other species, not clearly visible. Ovaries reflexed through one third of length of oviduct and uterus. Ovaries half as wide as body. Oocytes in a single row. Intestine passes to the left of anterior and right of posterior ovary. Prerectum absent. Rectum straight, length two-thirds anal-body width. Anal lips slightly protuberant. Tail 15 per cent of total length;
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\1.
I j I I I / I / / E
Fig. 1. lotonchus basidontus. A. head region; B. en face view of lip region; C. oesophago-intestinal junction; D. lateral view of vulva; E. male tail; F. spicules and gubernaculum; G. female tail. MONONCHIDAE OF NEW ZEALAND II 263
ventrally arcuate, conoid in proximal half, then cylindrical, tip rounded. Caudal glands and terminal duct present. Lateral cuticular pores as shown in fig. 1 G. Male Testes paired, opposed, outstretched. Anterior testis five-sixths as long as posterior. Vas deferens equal to half testicular length. At a level between the second and third supplement the vas deferens swells to become the ejaculatory duct which opens into the cloaca. Prerectum equal to ejaculatory duct in length. Spicules paired, long, slender, free. Gubernaculum small, simple, without lateral processes. Lateral accessory pieces wanting. Supplements fourteen, small, papilli- form, equidistant. Tail similar to female. Caudal glands with terminal duct present. Lateral cuticular pores as in fig. 1 E. Specific differentiation. I. basidontus most closely resembles I. gymnolaimus (Cobb) and I. consimilis (Cobb); two species which need redescription. From these I. basidontus is distinguished by the presence of paired ovaries, the head which is not offset, the shape of the amphid (duplex in I. consimilis), the thickness of the stoma wall (thin in I. gymnolaimus) and the tail shape (tip swollen in I. gymnolaimus). Type slides. In nematode collection, Entomology Division, D.S.I.R., Nelson, N.Z. Type locality. Ross, Westland in Lolium perenne L.-Trifolium repens L.-An- thoxanthum odoratum L. pasture. Soil type: Hokitika fine sandy loam (a recent alluvial soil derived from schist). Other localities. Kumara Beach, Hydrocotyle L. sp. — Trifolium repens L. turf; Awatuna, water-logged soil with Ranunculus L., Hydrocotyle L. and Juncus L.; Awatuna-Stafford, Carpodetus serratus Forst.-1Veinmannia racemosa Linn. fil. scrub; Hokitika, mental hospital terrace, swampy land with sedges, Juncus L., and Drosera L. spp.; Hongi's Track, Beilschmiedia Tawa Benth. & Hook f.-Knightia excelsa R. Br. forest litter; Kiripaka, Beilschmiedia Taraire Benth. & Hook. f.- Vitex lucens T. Kirk forest litter. Remarks Several specimens had rhabditids and tylenchids in the intestine. There appear to be no grounds for separating the Awatuna female from the others, though the measurements indicate a larger animal with a slightly shorter oeso- phagus.
lotonchus maragnus n. sp. Figs. 2 A-I Sergeants Hill Holotype ? L = 4.22 mm; a = 69; b = 7.14; c = 2.95; V = 6 35.9 ' Paratype 1 ? L = 3.64 mm; a = 59; b = 6.33; c = 2.31; V = 15 38.9 10 Westport Pakihi Allotype d L = 3.3 mm; a = 53; b = 6.24; c = 2.66; T = 24 Cuticle 1.5 p, thick with obsolescent fine annuli in caudal region. No lateral fields. Subcuticle 2.5 tu thick. Body tapers slightly anteriorly; lip region offset by slight constriction. In lateral view lips closely approximated. Amphids small, cup-
264 W. C. CLARK like, aperture a transverse slit. In en face view lip region almost circular; divided into six equal segments. Inner lip margins pointed, outer margins rounded. Pa- pillae in two rings; inner ring of six and outer ring of ten (two papillae on each
A
C
0 0
D
Fig. 2. lotonchus maragnus, A. head region; B. en face view of lip region; C. oesophago-intestinal junction; D. lateral view of vulva; E. female tail; F. anal region of male; G. female tail; H. spicule, gubernaculum and lateral accessory piece; I. supplements. MONONCHIDAE OF NEW ZEALAND II 265
of the submedian lips and one on each lateral). Amphid apertures crescentic in this view. In lateral view stoma barrel-shaped, broad at base, three-quarters as wide as long, length equal to head width. Dorsal tooth apex at 59-61 per cent of stoma length. Anterior edge of tooth straight, horizontal; posterior edge intersects dorsal stoma wall at suture between anterior and posterior elements. Apart from dorsal tooth, ventral and dorsal stoma walls similar, in-arched anteriorly. Anterior stoma aperture two-fifths of greatest stoma width. Posterior elements similar. Outer surface of stoma with fine transverse striae. Anterior four-fifths of stoma within thin muscle sheath; posterior fifth embedded in expanded end of oesophagus. Oesophagus narrows a little to nerve ring at one-third of its length where it occupies half body-width, then gradually expands to three-fifths body-width. Oeso- phageal gland ducts occur at 44, 63-67, and 93-96 per cent of the oesophageal length. Oesophago-intestinal junction tuberculate, funnel-shaped valve not seen. Posterior face of sphincter muscle with several large glandular (?) cells. Intestine as usual. Female Vulva transverse. Vagina thick walled, extending across one third to half body-width. No radiating muscles seen. Uteri paired, opposed, outstretched, with conspicuous sphincter muscle and glandular region at uterus-oviduct junc- tion. Ovary half as wide as body, reflexed through one sixth length of oviduct and uterus. No pre-rectum. Rectum straight, equal to anal-body-width. Tail ex- tremely attenuated, filiform, approximately one-third of body length. Caudal glands present, terminal duct absent. Caudal cuticular pores as in fig. 2 E. Male Testes paired, opposed, outstretched. Length of testes equal to length of vas deferens. Vas deferens enlarged posterior to second supplement where it be- comes the ejaculatory duct. Ejaculatory duct and prerectum equal. Supplements twelve, small, low, almost equidistant. Spicules paired, free, slender, curved, with thickened median strand in distal three-quarters, tips bifid, head sigmoid. Paired, notched, lateral accessory pieces present. Gubernaculum large, thickened behind the spicules, lateral processes large, thin, partly enveloping the spicules and lateral accessory pieces. Tail similar to female. Specific differentiation. The extremely long whip-like tail 34-43 per cent of the total length readily separates I. marag,nus from all other species in the genus except I. trichurus Cobb and 1. percivali n. sp. It is distinguished from I. trichurus by the paired ovaries and larger size and from 1. percivali by the more anterior position of the vulva, the slightly longer tail and the smaller size. In the only males available there are twelve supplements in I. maragnus and eighteen in I. percivali. Type slides. Entomology Division, D.I.S.R., Nelson, N.Z. Type locality. Sergeant's Hill, Pakihi, N.Z.M.S.1. S23/24, 135724, 30 metres. Vegetation Gleichenia circinata Swartz, Leptospermum scoparium Forst., Cla- clium teretifolium R. Br., Sphagnum falcatulum Bresch. Soil: Sergeant series (gley podsols).
266 W. C. CLARK
Other locality. Westport Pakihi, vegetation as above. Remarks A nemativorous species; food in the intestine includes larvae of its own species. Both localities with wet, mature gley podsol soils. The specific name alludes the whip-like tail (Greek ii.CLp' = whip).
lotonchus ophiocercws n. sp. Figs. 3 A-H Holotype (Barrytown) L = 4.03 mm; a = 41; b = 4.75; c = 4.88; V = 12 56.6 10 Allotype d (Waimangaroa) L = 3.82 mm; a = 46; b = 5.17; c = 5.76; T = 15 Paratypes (Barrytown) 2 yy L = 3.82 mm; a = 45-47; b = 4.81-4.85; c 4.68; V = 9-1° 53.9-61.9 54°
(Kumara Beach) L = 3.98; a = 44; b = 4.92; c = 5.21; V = 54.5 6 L= 3.75 mm; a = 38; b = 4.58; c = 10.5; T = 24.6 Cuticle 3 p. thick, with exceedingly fine annuli only visible under very favour- able conditions, usually appearing smooth. No lateral fields. Subcuticle 2 p, thick. Lip region scarcely offset. Lips rather closely approximated. Amphids cup-shaped; aperture narrow, elliptical, situated at level of anterior limit of stoma walls. En face view (of larva) shows a rounded hexagonal lip region, lips equal, inner edges pointed. Papillae in two rings, inner ring of eighteen papillae, (three on each lip arranged in an obtuse triangle), outer ring of ten papillae. Abutting edges of the stomal elements slightly thickened on the inner side only. In lateral view stoma barrel-shaped, broadly rounded at base; anterior aperture four-fifths of maximum stoma width. Dorsal tooth apex at 54-60 per cent of stoma length. Tooth apex sharply pointed, anterior edge slightly convex, almost horizontal; lower edge slightly convex in middle and merging with lower stoma wall a short dis- tance anterior to the suture between the anterior and posterior elements. Dorsal wall indented below tooth. Anterior parts of dorsal and ventral walls similar, incurved anteriorly, ventral wall appears slightly thicker due to thickening at abut- ting edges of subventral elements. Dorsal posterior element shorter and thicker than subventrals. Suture between anterior and posterior elements clearly marked. Outer surface of stoma with fine transverse striae. Anterior four-fifths of stoma enveloped in thin muscle sheath; posterior fifth embedded in locally expanded oesophagus. Oesophagus narrows rapidly behind stoma base to about half body-width and remains this width to nerve ring at one-third of its length, then gradually ex- panding to half body-width in conformity with general body contour. Dorsal oeso- phageal gland opens into oesophagus near middle; subventral glands discharge into posterior third.
MONONCHIDAE OF NEW ZEALAND II 267
Fig. 3. lotonchus ophiocercus. A. head region; B. en face view of lip region of larva; C. oesophago- intestinal junction; D. tail of paratype male; E. detail of gubernaculum, lateral accessory piece and spicule; F. tail of male allotype; G. female tail; H. tail tip.
268 W. C. CLARK
Oesophago-intestinal junction tuberculate. Intestine a simple tube eight to twelve cells in diameter; cells packed with oil globules and dark granules. Female Vulva transverse. Vagina with well developed musculature, extending half way across body. Uteri paired, opposed, outstretched, with a well developed sphincter muscle and glandular zone at the uterus-oviduct junction. Ovary reflexed through one-fifth of oviduct and uterus length. Ovary half as wide as body. A few cuticular pores sometimes present in the region of the vulva. Intestine passes to right of anterior ovary and to left of posterior one. Prerectum absent. Rectum straight, one anal-body-width long. Posterior anal lip slightly protuberant. Tail very long, equal to one-fifth of the body length; tapering smoothly, ventrally arcuate, tip rounded. Caudal glands and sub-terminal duct present. Cuticular pores as shown in figure 3 G. Male Testes paired, outstretched, opposed, sperms abundant; not arranged in any pattern. Vas deferens equal to testicular length; greatly dilated posterior to third supplement to become ejaculatory duct. Anterior half of ejaculatory duct much wider than posterior. Prerectum commences opposite fourth supplement. Spicules paired, free, slender, especially in distal half; heads knobbed; one and a quarter anal-body-widths long. Gubernaculum similar to that of I. maragnus. Lateral accessory pieces notched. Supplements eleven or thirteen, each with a low rounded papilla. Allotype male tail similar to female. Paratype male tail much shorter than other male or females. Caudal glands present; terminal duct not seen. Specific differentiation. I. ophiocercus is unique in possessing a long tail (c — about 5), and a tooth the apex of which lies near the middle of the stoma. Some species have a tail as long, or longer than ophiocercus (e.g. trichurus, tenuiden- tatus, maragnus and percivali), but all these have the tooth apex clearly in the posterior half of the stoma. Type slides. All in Nematode Collection, Entomology Division, D.S.I.R., Nel- son, N.Z. Type locality. Johnson's Reserve, Barrytown, N.Z.M.S.1., S 37, 847223, 30 metres, in forest dominated by lVeinmannia racemosa Linn. f. and tree ferns. Soil Ikamatua fine sandy loam (an immature podsol). Other localities. Kumara Beach in Hydrotyle L.-Trifolittnz repens L. turf; Crai- gielachie, Otago in Agrostis tenuis L.-Dactylis glomerata L.-Trifolium repens L. pasture; Collingwood Pakihi, Cladium teretifolium R. Br., Gleichenia circinata Swartz, Drosera pygmaea DC.; Wharekohe, Gleichenia circinata Swartz, funcus L. sp. Leptospermum scoparium Forst. Remarks. This species has been collected from wet podsolic soils only. Many specimens had nematode remains in the intestine; dorylaimoid spears and spicules as well as I. ophiocercus stomas have been seen. The name is derived from the nature of the tail ( 6yr.c — a serpent, x6pxo5 — a tail). MONONCHIDAE OF NEW ZEALAND II 269
lotonchus parazschokkei (AlIgen) Figs. 4 A-F Afononchus parazschokkei AlIgen, 1929 p. 224 figs. 6a, b. Mononchus (lotonchus) parazschokkei Goodcy 1951 p. 272 lotonchus parazschokkei Andrassy 1958 p. 159 Males unknown. (For measurements of females see Table I).
A 20011 , D 50.0 .A.F. 50 .0
Fig. 4. lotonchus parazschokkei. A. head region; B. en face view of lip region; C. oesophago- intestinal junction; D. female reproductive organs; E. ventral view of vulva; F. female tail.
Cuticle smooth, 3 p. thick; no lateral fields. Subcuticle 1 p. thick. Lip region scarcely offset. Amphids small, cup-like; aperture oval, situated posterior to outer lateral cephalic papilla. In en face view lip region hexagonal; lips equal and sym- metrical, inner lips rounded, outer lips angular; inner ring with six papillae, outer TABLE I Measurements of Iotonchus parazschokkci females
Hongis Mt. Arthur's Waitaanga Lake Kerikeri Rerewhakaitu Track Messenger Pass Barrytown Saddle Mahinapua n 4 10 2 1 18 2 10 11
L (mm) mean 1.28 1.50 1.57 1.79 1.90 2.20 2.34 2.37 kk *i S.D. (mm) ± 0.041 ± 0.111 ± 0.151 ± 0.207 -4- 0.183 'D Range 1.21-1.31 1.27-1.61 1.49-1.65 1.79 1.67-2.11 2.13-2.26 1.84-2.57 2.04-2.64 a 25-35 27-34 27-28 36 27-34 28-29 29-35 29-37 IM NIT b 3.4-3.5 3.7-4.2 3.6 3.9 3.7-4.2 4.0-4.1 3.7-4.6 3.8-4.6 c 10.7-11.2 10.9-14.2 9.5-9.8 8.4 10.9-14.2 12.8-14.9 9.3-15.2 8.8-13.4 a.o. 1) 8-11 6-17 8-9 12 6-17 11-14 10-18 6-14 V 61-63 58-65 61-63 59.3 58-65 62-63 58-63 57-61 p.o. 1) 8-10 8-13 8-10 9 8-13 11-14 10-16 8-13
1) a.o. and p.o. anterior and posterior ovaries respectively. MONONCHIDAE OF NEW ZEALAND II 271
ring with ten. Inner papillae situated on eminences near middle of each lip; outer papillae near the tips of the lips. Stoma circular in cross section. In lateral view stoma heavily sclerotized, ovate, anterior end widest. Stoma widest at 47-55 per cent of its length. Dorsal tooth apex occurs at 46-56 per cent of the stoma length. Anterior edge of tooth straight or nearly so, sloping slightly posteriorly. Posterior edge of tooth slightly convex, quickly merging with general contour of posterior portion of stoma wall. Posterior to dorsal tooth outer surface of stoma is indented. Anterior to tooth dorsal wall is similar to, but thinner than the gently curving, anterior, ventral wall. The dorsal posterior element thicker and shorter than ventral ones. Posterior fifth of stoma embedded in slightly ex- panded end of oesophagus. Anterior four-fifths surrounded by a thin muscle sheath. Oesophagus narrows a little to nerve ring, at one-third of its length, and then expands again, generally occupying half of body width. Oesophago-intestinal junction tuberculate with a well developed sphincter muscle. Intestine as usual. Vulva o transverse slit, one-third as wide as body, with thickened lips. Vagina thick walled, extending half way across body. Uteri paired, outstretched, opposed, and reflexed through half length of oviduct and uterus. Usually one or two eggs in the uteri at a time. No prerectum. Rectum slightly arcuate, one to one and a quarter anal-body- widths long. Tail short, conoid, ventrally arcuate. Caudal glands present. No ter- minal duct. Three pairs of lateral cuticular pores present distributed as in fig. 4 F.
Specific differentiation. I. parazschokkei is similar to I. amphigonicus (Thorne) and 1. zschokkei (Menzel), but is distingu;shed by the longer tail. Localities. Arthur's Pass and Takaka. Hill in Nothofagus Blume forest litter; Lake Mahinapua in Dacrydium cupressinum Soland-Quintinia acutifolia T. Kirk forest litter; Barrytown in 1Veinmannia racemosa Linn. f.-tree fern litter; Four Mile River, Buller, and Sergeant's Hill from soil under Gleichenia circinata Swartz and Sphagnum; Iron Hill, Cobb River soil under Carpha alpina R. Br.; Kerikeri soil under Leptospermum scoparium Forst. and Hakea acicularis R. Br.; Kiripaka Beilschmiedia Taraire Benth. & Hook. f.-Vitex lucens T. Kirk forest litter; Hongi's Track Beilschmiedia Tawa Benth. & Hook. f.-Knightia excelsa R. Br. forest litter; Rerewhakaitu soil under Leptospermum scoparium Forst. and Poa caespitosa Forst.; Waiotapu Dacrydium cupressinum Soland.-1Veinmannia racemosa Linn. f. forest litter; Waitaanga Saddle in liverworts and mosses; Mt. Messenger Olea Cunning- hainii Hook. f.-Vitex lucens T. Kirk forest litter. Remarks. This species varies in length, but there are no conspicuous breaks in the series of measurements, or morphological differences between the largest and smallest specimens. It inhabits soil, moss and litter. 272 W. C. CLARK
lotonchus percivali n. sp. Figs. 5 A-I Holotype (Runanga) L = 5.94 mm; a = 71; b = 5.02; c = 3.79; V = 13 51.5 13 Allotype d (Reefton) L = 6.10; a = 74; b = 5.06; c = 4.15; T = 31 Cuticle 4 µ thick, smooth on body, annulated on tail. No lateral fields. Sub- cuticle 3 p. thick. Lip regions slightly offset, lips closely apposed, almost fused. Amphids cup-like; aperture narrow, situated near anterior end of sclerotized stoma. In en face view lip region circular, lateral lips smaller and more pointed on inner edge than sub-median lips. Outer edge of lips rounded. Papillae in two rings of six each. In lateral view sclerotized stoma is barrel-shaped, base broad; greatest width at one-quarter of its length where it occupies three-quarters of body-width. Dorsal tooth apex at 63 per cent of stoma length. Anterior edge of tooth straight, horizontal; apex rather blunt. Posterior edge of tooth intersects stoma wall at suture between anterior and posterior elements. Dorsal and ventral walls similar. Dorsal posterior element slightly thicker than subventrals. Suture between anterior and posterior elements distinct. Outer surface of stoma transversely striated. Sub- dorsal and sub-ventral cuticular pores near widest part of stoma. Muscular sheath about anterior part of stoma very thin. Anterior end of oesophagus expanded about stoma base, then narrowing to half body-width at nerve ring at one-fifth of oesophageal length, gently expanding beyond this to two-thirds body-width. Oeso- phago-intestinal junction tuberculate. Intestine with abundant oil droplets and dark granules.
Female Vulva transverse. Vagina thick walled, extending across half body-width. Uteri paired, outstretched, opposed, a strong sphincter and glandular region at uterus-oviduct junction. Upper part of uterus in holotype filled with sperm. Ovary half as wide as body, reflexed through one-third length of oviduct and uterus. Intestine passes to left of anterior ovary, and to right of posterior one. No pre- rectum; rectum slightly arcuate, length almost equal to anal-body-width. Tail ven- trally flexed when fixed, long (26 per cent of body length), filiform, tip rounded. Caudal glands and terminal duct present. Cuticular pores few on proximal part of tail, more common on annulated distal two thirds.
Male Testes paired, opposed, outstretched, with abundant sperm randomly ar- ranged. Vas deferens length equal to both testes. Opposite first supplement vas deferens expands to become ejaculatory duct, and the intestine narrows to form prerectum. Spicules paired, free, moderately heavy, knobbed on upper end with a thickened median rib on distal 85 per cent. Gubernaculum with thickened keel behind spicules and with lateral pieces which flank spicules. Parallel to and a little in front of lateral processes are notched, lateral accessory pieces. Supplements eighteen, low, papilliform, with rather sigmoid "cores". Tail similar to female.
MONONCHIDAE OF NEW ZEALAND II 273
Fig. 5. lotonchus percivali. A. head region; B. en face view of lip region; C. oesophago-intestinal junction; D. posterior limb of female reproductive system; E. male supplements; F. anal region of male; G. spicule, gubernaculum and lateral accessory piece; EL male tail; I. female tail. 274 CLARK, MONONCHIDAE OF NEW ZEALAND II
Specific differentiation. Another species of the long-tailed group of /otonchus; readily distinguished from all others by its large size, paired ovaries, median vulva and long tail. Type slides. Entomology Division, D.S.I.R., Nelson, N.Z. Type locality. Runanga, Westland, N.Z.M.S.1. S44, 774951, 20 metres. Very wet pacture, Holcus lanatus L., Agrostis tenuis L., Juncus L. sp., Ranunculus repens L.; soil: Karangarua fine sandy loam—a recent, poorly drained alluvial soil. Other locality. Reefton in Sphagnum swamp. Remarks. This species is named in honour of my teacher, the late Prof. E. Per-' cival, of the University of Canterbury.
ZUSAMMENFASSUNG Die Mononchiden (Enoplida, Nematoda) Neu-Seelands. 2. Die Gattung Iotonchus (Cobb, 1916) Altherr 1950. lotonchus (Cobb, 1916) Altherr 1950 wurde neu definiert. Die Gattung unterscheidet sich von Mononchus Bastian durch die tuberkulate Verbindung vom Oesophagus zum Darm, den Dorsalzahn, der ganz oder hauptsachlich in der hinteren Halfte der Mundhohle liegt, und durch die breite Basis der Mundhohle. I. jairi (Lordello, 1959) n. comb. und I. tenuideniatus (Kreis 1924) n. comb. wurden aus der Gattung Mononchus in die Gattung lotonchus iiberfiihrt. I. basidontus n. sp. unterscheidet sich von I. gymnolaimus und I. consimilis durch den Besitz von paarigen Ovarien. I. maragnus n. sp. ist durch den Besitz eines sehr langen fadenfOrmigen Schwanzes (c = 2,3 bis 2,9) und die Lage der Vulva (V = 36-39) charakterisiert. I. ophiocercus n. sp. ist die einzige langgeschwanzte Art der Gattung mit der Zahnspitze nahe der MundhOhlen- mitte. I. percivali n. sp. ist die grosste Art der Gattung (L = 6 mm). Sie hat einen langen Schwanz (c = 3,8 bis 4,1), eine mittelstandige Vulva und paarige Ovarien. I. parazschokkei (Allgen 1929) wurde neubeschrieben. REFERENCES ALTHERR, E. (1950). Les nematodes de Parc National Suisse. Ergebn. wiss. linters. schweiz. Nat Parks III 1-46. ANDRASSY, I. (1958). 'Ober das System der Mononchiden (Mononchidae Chitwood, 1937; Nema- toda). Ann. Hist.-nat. Mus. hung., n.s. 9, 511, 151-171. CLARK, W. C., (1960). The oesophago-intestinal junction in the Mononchidae (Enoplida; Nema- toda). Nematologica, 5, 178-183. COBB, N. A. (1916). Notes on new genera and species of nematodes. 4. Subdivisions of Mononchus. J. Parasit. 2, 195-196. — (1917). The Mononchs (Mononchus Bastian, 1865) a genus of freeliving predatory nema- todes, Soil Sci. 1, 431-486. PENNAK, R. W. (1953). Freshwater Invertebrates of the United States. New York, Ronald Press Co. 769 pp.
Received for publication: September 12, 1960. Section HIGHER TAXONOMY 1961] 123
1. A REVISED CLASSIFICATION OF THE ORDER ENOPLIDA (NEMATODA)
By W. C. CLARK, Rothamsted Experimental Station, Harpenden, Herts, England. *
(Received for publication, 5 December 1960) Summary The order Enoplida is re-classified into seven sub-orders mainly on the basis of the arrangement of the oesophageal glands and their ducts. The sub-orders recognised are Enoplina, Alaimina n. sub-order, Dorylaimina, Trichosyringina (composed of the Mermithoidea and Trichuroidea) and Dioctophymatina. The Mononchidae are removed from the Tripyloidea and with the Bathyodontidae n. fain. (type genus Bathyodonttts Fielding, 1950) comprise the Mononchoidea n. superfamily within the Dorylaimina. The Belondiridae and Nygolaimidae have been redefined, Nygellus Thorne, 1939 is transferred from the former to the latter and the Nygolaimellinae n. subfam. (type genus Nygelolaimellus Loos, 1949) erected. The Campydorinae are removed from the Leptonchidae and elevated to family rank. The Trichodorinae are given family rank, and with the Diphtherophoridac form the Diphtherophoroidea within the Dorylaimina. In the Trichuroidea four families and four subfamilies are recognised (Table 1). Skrjabin & Schikhobalova's 1954 proposal to unite the Trichuroidea with the Dioctophymatina is rejected on the grounds of morphology and life history. It is considered that the life history of Dioctophyme renale indicates a relationship between the Dioctophymatina and the Gordiacea. The name Octonchus nom. nov. is proposed pro Polydontus Schultz, 1932 preocc., nec. Polydontus Blainville, 1826 a mollusc.
INTRODUCTION Filipjev (1934) and Chitwood (1937) have rendered a signal service to nematology in leading the way towards a satisfactory classification of the Nematoda as a whole. Chitwood's (1937) classification was reprinted in expanded form in Chitwood and Chitwood's (1937) "Introduction to Nematology", and again with some modifications in the revised edition of 1950. T. Goodey (1951) in "Soil and Freshwater Nematodes" used the Chitwoods' 1937 classification for the most part, with modifications from Thorne (1939) in the Dorylaimoidea. The later works of the Chitwoods, T. Goodey, and Thorne have firmly established the main points of Chit- wood's 1937 classification of the Enoplida for workers on soil and plant parasitic nematodes. Workers on marine nematodes use a slightly different classification; e.g. 'Wieser (1953a) regards all the subfamilies of the Eno- plidae as families. The taxonomy of the Enoploidea needs extensive study; that proposed here will suffice in the interim. Because of the small number of animal parasitic genera contained within the Trichuroidea and the Dioctophymatina animal parasitologists have, with the exception of Russian workers, been little concerned of late with the higher classification of this order. The exception is Skrjabin & Schikhobalova in Skrjabin, Schikho- balova, Sobolev, Paramonov & Svaarikov (1954) who have proposed a number of changes in the classification of these forms. The suggested changes include the removal of the Trichocephalata (suborder) Skrjabin &
*At present on study leave from Entomology Division, D.S,I.R., Nelson, New Zealand.
N,Z, J. Sri, 4: 123-50. 124 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
Shultz, 1928 (= Trichuroidea Railliet, 1916) from the Enoplida and uniting them with Dioctophymata Skrjabin, 1927 (suborder) under the name Trichocephalida Spasski, 1954 in Skrjabin et al., 1954. No reasons are given for these changes. If the Trichuroidea are to be united with any other group at the ordinal or subordinal level their logical partners are the Mermithoidea with which they share many features, e.g. the oesophageal glands are represented by a stichosome outside the contour of the oesophagus, pore-like amphids, often a single spicule, and the presence of a stylet in the larval stage which, as Fiilleborn (1923) pointed out, suggests an affinity between the two groups. The stylet occasionally persists in adults of both superfamilies. The Dioctophymatina on the other hand are characterised by the presence of highly polynucleate oesophageal glands, which discharge anteriorly, con- tained within the contour of the oesophagus, and a conspicuous caudal sucker in the males — all features not found in the Trichuroidea. Wood- head (1950) has confirmed the observation of Lukasiak (1930) that the first stage larva of Dioctophyme renale possesses a stylet. This may be regarded as indicative of an affinity between the dioctophymatids, the trichurids, mermithids, and the dorylaimids, and would justify the reten- tion of all these groups within the Enoplida. Primarily because of the differences in the arrangement of the oesophageal glands, and because of the occurrence of a Gordius-like stage in the life history I prefer to keep the Dioctophymatina separate from the Trichuroidea, though admitting a degree of affinity on other grounds as suggested by Rauther (1918). The great similarity of life history and of the morphology of larval stages of Dioctophyme renale (Woodhead, 1950) and gordiids appears to indicate that these two groups may be much closer phylogenetically than has hitherto been supposed. The presence of a dorylaimoid oesophagus in the Tetradonematidae, a dorylaimoid spear in all mermithid larvae, and of cyathiform amphids in some, as well as the pre-anal supplements in males point as Steiner (1917) and Filipjev (1934) have suggested, to an affinity between the Mermithidae and the Dorylaimoidea. In the work which follows Skrjabin et al's pro- posals are rejected. Hyman (1951) gave a classification of the Nematoda into 17 orders without higher groups. The diagnoses are vague and insufficiently precise to be useable. The Chitwoods' (1937) division into two main groups Phas- midia or Sercenentea, and Aphasmidia or Adenophorea is retained as a matter of taxonomic expediency. The usefulness of these divisions in prac- tical nematology is doubtful. The present study arose out of the writer's work on the Mononchidae (Clark, 1960 a, b, c 1961 a, b c) during the course of which it became apparent that the Mononchidae had very little in common with the rest of Chitwood's Tripyloidea, but much in common with the Dorylaimoidea. As it is now over twenty years since Chitwood's classification was erected and as much new knowledge has become available in the meantime the opportunity is taken to incorporate this into the existing framework and to make such changes as seem necessary.
1961] CLARK — ENOPLIDA (NEMATODA) 125
TAB LE 1—Proposed Classification of the Enoplida
Order ENOPLIDA
Suborder Superfamily Family Subfamily
( Enoplinae lJ Leptosomatinae rENOPLIDAE Phanodermatinae Oxystominae E NOP LO IDEA LAURATONEMATIDAE Oncholaiminae 0 NCHOLAIM IDAE Eurystominae ENOPLINA Enchilidiinae
TRIPYLOIDEA TRIPYLIDAE Ironinae {IRONIDAE Cryptonchinae
ALAIMINA A LAIMIDAE
'MONONCHOIDEA MONONCHIDAE BATIIYODONTIDAE
Dorylaiminae DORYLAIMIDAE Actinolaiminae {Tylencholaiminae OPAILAIMIDAE DORYLAIMINA BELONDIRIDAE DORYLAIMOIDEA
Nygolaiminae 1 NYGOLAIMIDAE Nygolaimellinae LE PTONCIIIDAE LCAM PYDORIDAE i_DIPIITHEROPIIOROIDEA DIPIITHEROPHORIDAE TRICHODORIDAE
MERMITIIOIDEA S ME RM ITHIDAE TETRADONEMATIDAE TRICHOSYRIN- GINA 1Trichurinae TRIGHURIDAE Capillariinae
TRICHUROIDEA Trichosomoidinae TRIGHOSOMOIDIDAE Anatrichosomatinae
TRIGHINELLIDAE CYSTOOPSIDAE
DIOCTOPHY- Dioctophymatinae DIOCTOPHYMATIDAE MATINA Eustrongylidinae SOBOLIPHYMATIDAE 126 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
PROPOSED CLASSIFICATION
Chitwood's classification into suborders is based in part on the nature of the oesophageal glands and their ducts. It is proposed to utilise this charac- ter more fully in the subdivision of the Enoplida. On this basis it is pos- sible to divide the order into five readily definable suborders (see Table 1 and Fig. 1). The type and arrangement of the oesophageal glands and their ducts in the different suborders is shown schematically in Fig. 1. In the Enoplina the oesophageal glands are uni- or multi-nucleate and at least three of the glands discharge into the oesophageal lumen anterior to the nerve ring, commonly in the stomatal region. In the Alaimina n. suborder there appears to be seven uninucleate oesophageal glands which discharge anterior to the nerve ring. The Dorylaimina are characterised by having five (only three in Leptonchus) usually uninucleate oesophageal glands with all the ducts posterior to the nerve ring. In the Trichosyringina the oesophageal glands lie outside the contour of the oesophagus as a sticho- some. Highly polynucleate, dichotomously branching oesophageal glands which lie within the contour of the oesophagus and which discharge anteriorly to the nerve ring characterise the Dioctophymatina.
C D E F G H Diocto- Alaimina Dorylaimina Trichosyringina phymatina
FIG. 1—Diagrams illustrating the various arrangements of the oesophageal glands and their ducts in the Enoplida. A. Enoploidea, B. Tripyloidea, C. Alaimidae, D. Mononchoidea, E. Dorylaimoidea, F. Cystoopsidae, G. Mermithoidea and Tri- churoidea excluding Cystoopsidae, H. Dioctophymatina. (Partly after Chitwood & Chitwood.) 1961] CLARK - ENOPLIDA (NEMATODA) 127
A D E F FIG. 2—Diagrams to illustrate the terminology used to describe types of oesophagus. A. cylindroid, B. conoid, C. crenate, D. multibulbar, E. dorylaimoid, F. bi-bulbar.
At the level of superfamilies fewer changes have been made. The con- ception of the Tripyloidea has altered somewhat since 1937. Thorne (1939) removed the Alaimidae to the Dorylaimoidea. In 1950 the Chitwoods moved the Ironidae from the Enopliodea to the Tripyloidea, but retained the Alaimidae in the Tripyloidea. In the present scheme the Alaimidae are transferred to a newly created suborder Alaimina. The Alaimidae did not conform with the other members of the Tripyloidea, nor with other mem- bers of the Dorylaimoidea. The Alaimina possess a number of dorylaimoid and tripyloid characters as well as some special ones of their own. These characters are mentioned in Table 2. The greatly reduced stoma of the Alaimids is reminiscent of some Ironidae and male Enchilidiinae. On balance it seems that the Alaimina may have an ancestry with much in common with the Tripyloidea and Dorylaimoidea, but have diverged along a different evolutionary line. The Mononchidae have also been removed from the Tripyloidea, and in combination with the Bathyodontidae n. fam. form the Mononchoidea within the Dorylaimina. The Mononchidae have very little in common with the Tripyloidea, but share the following features with the Dorylaimoidea: similar arrangement of the oesophageal gland cells and their ducts; the absence of cephalic setae; a greatly reduced excretory system; the common occurrence of a sphincter muscle and glandular region at the junction of the 128 NEW ZEALAND JOURNAL OF SCIENCE [MAR. oviduct and uterus (T. Goodey, 1942, J. B. Goodey, Peacock and Pitcher 1960, Clark 1961 b, c) ; the large number of preanal supplements ; the presence of cuticular caudal pores, and the occupation of the same general type of habitat.
TABLE 2—The Distribution of Certain Characters in the Alaimina, Dorylaimoidea, and Tripyloidea
Character ALAIMINA DORYLAINIOIDEA TRIPYLOIDEA
Stoma unarmed, reduced seven oesphageal glands testis single oesophagus dorylaimoid pair of adanal supplements present -I- prerectum present spicules tripyloid oesophageal gland ducts ant. to nerve ring gubernaculum present caudal glands present cephalic setae present 4-
The Dorylaimoidea have been further restricted to exclude the Diphthero- phoridae (sense Thorne, 1939) which have been raised to superfamily rank. The presence of the Diphtherophidae within the Dorylaimoidea has long been a matter of doubt, and because they differ from the rest of the Dorylaimoidea in so many characters e.g. a different type of spear, the presence of a gubernaculum, a distinct excretory pore, an unpaired testis, and the absence of a prerectum and adanal supplements it is considered advisable to remove them from the Dorylaimoidea. This action emphasises their distinctive characters and makes the Dorylaimoidea a more compact group. The Diphtherophoroidea may have to be removed from the Dorylai- mina in the future. In the following section the changes which have been made in the families, subfamilies and the distribution of genera and species are noted after the diagnoses of the relevant groups.
DIAGNOSES In the diagnoses information given in the higher categories is not men- tioned again in the lower ones except to restrict the diagnoses of the lower category. In the lists of genera synonyms are not new unless marked as such. 1961] CLARK - ENOPLIDA (NEMATODA) 129
Order ENOPLIDA Adenophorea. Amphids pocket-like to pore-like or tuboid; caudal glands present or absent; subventral oesophageal glands opening either near anterior end of oesophagus or in posterior half; glands sometimes dupli- cate, rarely polynucleate; or outside the contour of the oesophagus as a stichosome; oesophagus cylindroid or conoid, rarely bi- or muti-bulbar, commonly with a narrow anterior part and a wider glandular posterior part, or greatly attenuated. Setae present or absent. Habitat — marine, freshwater, soil, parasitic in arthropods and vertebrates.
Suborder ENOPLINA Enoplida. Head usually bearing 6 + 10, 10, or 6 + 4 setae (setae absent in a few scattered genera) ; amphids usually pocket-like; typical stylet absent; three or more oesophageal glands opening in the stomatal region, glands mostly uninucleate; oesophagus grossly cylindrical, conoid; or multibulbar; intestine functional; ovaries reilexed, female reproductive system simple; male with two spicules (very rarely none or one) ; muscular caudal sucker absent; caudal glands usually present; hypodermal glands commonly well developed; excretory system absent or consisting of one ventral cell. Polymyarian or meromyarian. Habitat — mainly marine or freshwater, some genera in moist soil.
Superfamily ENOPLOIDEA Schuur.-Stekh. & de Coninck, 1933 Enoplina. Cuticle of head duplicate; males with 0, 1 or 2 supplements.
Family ENOPLIDAE Baird, 1853 Enoploidea. Stomatorhabdions poorly sclerotised; with or without man- dibles; without a distinct stomatal capsule; stoma surrounded by oesopha- geal tissue. Type genus: Enoplus Dujardin, 1845.
Subfamily ENOPLINAE Micoletzky, 1922 Enoplidae. With three bifurcate mandibles; oesophagus cylindrical; amphids pocket like; males with one tuboid preanal supplement. Type genus: Eno plus Dujardin, 1845.
Other genera— Enoploides Savaljav, 1912 Paramesacanthion Wieser, 1953 Enoplolaimus de Man, 1893 Parasavaljevia Wieser, 1953 Enoplonema Kreis, 1934 Parenoplus Filipjev, 1927 Epacanthion Wieser, 1953 Rhabdodemania Bayliss & Daubney, Hyalacanthion Wieser, 1959 1926 Mesacanthion Filipjev, 1927 Savaljevia Filipjev, 1927 Mesacanthoides Wieser, 1953 Trichenoplus Mawson, 1956 Metenoploides Wieser, 1953 n. syn. Filenoplus Mawson 1956 Oxyonchus Filipjev, 1927 Sig. 9 130 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
Genera doubtfully included— Chaetonema Filipjev, 1927 Fenestrolaimus Filipjev, 1927 Donsinerna Allgen, 1949
Subfamily LEPTSOMATINAE Micoletzky, 1922
Enoplidae. Without mandibles; posterior part of oesophagus distinctly muscular; oesophagus usually cylindrical, rarely conoid, never vesiculate; subventral oesophageal glands may be multinucleate. Amphids pocket-like; males with one or two tuboid supplements (rarely absent, Stenolaimus). Type genus: Leptosomatum Bastian, 1865.
Other genera— Anticoma Bastian, 1865 Paranticoma Micol. & Kreis, 1930 Anticornopsis Micol. & Kreis, 1930 Platycoma Cobb, 1893 Antopus Cobb, 1913 Platycontopsis Ditlevsen, 1926 Barbonema Filipjev, 1927 (syn. Dactylonerna Filipjev, 1927) Cylicolaimus de Man, 1890 Stenolaimus Marion, 1870 (?syn. Nudolaimus Allgen, 1929) Synonchus Cobb, 1893 lagerskiNdia Filipjev, 1916 (syn. Fiacra Southern, 1914) Leptosomatides Filipjev, 1918 T horacostoma Marion, 1870 Leptosomatina Allgen, 1951 (syn. Deontostoma Filipjev, 1916) Leptosomella Filipjev, 1927 Triodontolaimus de Man, 1893 Metacylicolainuts Schuur.-Stekh., Tubolaimella Cobb, 1933 1946
Genus doubtfully included— Xennella Cobb, 1920
Subfamily PHANODERMATINAE Filipjev, 1927
Enoplidae. Amphids not elongate; mandibles absent; stoma rudimentary; oesophagus conoid, posterior part crenate in outline, muscles reduced; 10 cephalic setae; male with one or two tuboid supplements. Type genus: Phanoderma Bastian, 1865 (syn. Cophonchus Cobb, 1920 and Heteroce- phalus Marion, 1870). Other genera— Crenopharynx Filipjev, 1934 Phanodermatina Allgen, 1939 Klugea Filipjev, 1927 Phanodermella Kreis, 1928 (? syn. Gullmarnia Allgen, 1929) Phanodermopsis Ditlevsen, 1926 Micoletzkia Ditlevsen, 1926 (syn. Galeonema Filipjev, 1927) Nasinema Filipjev, 1927 1961] CLARK — ENOPLIDA (NEMATODA) 131
Subfamily OXYSTOMININAE Micol. 1924
Enoplidae. Stoma unarmed; oesophagus conoid with smooth outline; musculature weak; cephalic setae usually 6, post cephalic setae 4; amphids usually elongate, often tuboid internally. Males without preanal supple- ments. Type genus : Oxystoma Biitschli, 1874 with two subgenera Oxystoma s. str. (syn. Oxystomatina Filipjev, 1918; Acoma Steiner, 1916; Schistodera Cobb, 1920; and Nemanemella Filipjev, 1927) and Nemanema Cobb, 1920.
Other genera—
Augustinema Cobb, 1933 Porocoma Cobb, 1920
Halalaimoides Cobb, 1933 T halassoalaimus de Man, 1893
Halalaimus de Man, 1888 Trefusia de Man, 1893 with subgenera— Halalaimus s. str. T ycnodora Cobb, 1902 (syn. Nuada Southern, 1914) Pachydora Wieser, 1953
Doubtful genera—
Asymmetrica Kreis, 1929 Paroxystomatina Micol., 1922
Family LAURATONEMATIDAE Gerlach, 1954
Enoploidea. Stoma lightly to moderately sclerotised, unarmed; oesophagus cylindroid, 10 cephalic setae, ovary single, anterior; uterus discharges into cloaca, no externally opening vulva. Males with one testis, no supplements or gubernaculum; spicules straight or nearly so. Cuticle distinctly annulated. Type genus : Lauratonema Gerlach, 1954.
Family ONCHOLAIMIDAE Baylis & Daubney, 1926
Enoploidea. Stomatorhabdions heavily sclerotised; stoma somewhat capsuli- form, only the posterior part surrounded by oesophageal tissue. Type genus: Oncholaimus Dujardin, 1845.
Subfamily ONCHOLAIMINAE Micol. 1922
Oncholaimidae. Oesophagus cylindroid, never crenate or multibulbar; supplement absent or pedunculate. Type genus : Oncholaimus Dujardin, 1845. 132 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
Other genera— Adoncho/aimus Filipjev, 1918 Octonchus nom. nov. pro Anoncholaimus Cobb, 1920 Polydontus Schultz, 1932, see below Anoncholaimus Schuur.-Stekh., 1950 Oncholaimellus de Man, 1890 Anoplostoma Biitschli, 1874 Oncholaintoides Chitwood, 1937 Cacolaimus Kreis, 1932 Oncholaimium Cobb, 1930 Convexolaimus Kreis, 1928 Pelagonerna Cobb, 1893 Dioncholaimus Kreis, 1932 (syn. Cavilaimus Wieser, 1952) Doryonchus Kreis, 1932 Pelagonemella Kreis, 1932 Filipjevia Ditlevsen, 1928 Phaenoncholaimus Kreis, 1932 Filoncholaimus Filipjev, 1927 Pontonema Leidy, 1856 Krampia Ditlevsen, 1928 (syn. Paroncholaimus Filip., 1916) Meroviscosia Kreis, 1932 Prooncholaimus Micol., 1924 Metaparoncholaimus de Coninck & Pseudopelagonema Kreis, 1932 Schuur.-Stekh. 1933 Steineriella Ditlevsen, 1928 Metoncholaimoides Wieser, 1953 Trileptium Cobb, 1933 nom. nov. Metoncholaimus Filipjev, 1918 pro Trilepta Cobb, 1920 Mononcholaimus Kreis, 1924 Vasculanema Kreis, 1928 Mononchulus Cobb, 1918 Viscosia de Man, 1890 Remarks. Wieser (1953) has already remarked that Anoncholaimus Schuur.-Stekh., 1950 is a homonym of Anoncholaimus Cobb, 1920. He also suggested that it may be synonymous with Pelagonema Cobb, 1893. In the meantime I prefer to leave this name to be dealt with by the next reviser who shall either confirm the synonymy or propose a new name. I propose the new name Octonchus for Polydontus Schultz, 1932 which is preoccupied by Polydontus Blainville, 1826 (a mollusc). Polydontus marinus Schultz, 1932 will become Octonchus marinas n. comb.
Subfamily EURYSTOMINAE Filipjev, 1934 Oncholaimidae. Oesophagus conoid, crenate, or multibulbar; stoma simi- lar in both sexes, large, divided by one or more bands, rings or rows of denticles into two chambers. Large tooth broad with a large base. Spicules short, arcuate, gubernaculum usually with a dorsal apophysis; males with two (rarely one or none) cup-like sclerotised supplements. Amphid aper- tures transverse, oval or reniform. Type genus: Eurystomina Filipjev, 1918.
Other genera— Bolbella Cobb, 1920 Megeurystomina Luc & de Coninck, Ditlevsenella Filipjev, 1927 1959 Ledovitia Filipjev, 1927 Pareurystomina Micol. & Kreis, 1930 T hdonchus Cobb, 1920
Subfamily ENCHILIDIINAE MiC01., 1924 Oncholaimidae. Oesophagus conoid, sometimes crenate or multibulbar; showing sexual dimorphism in the stomatal region, males without a stoma, females and larvae generally with a stoma divided by a number of trans- 1961] CLARK - ENOPLIDA (NEMATODA) 133 verse rings (sometimes faint and irregular giving the impression of two chambers in Calyptronema) into several chambers. Large tooth of female slender, spine-like with a narrow base. Amphid aperture roundish or longi- tudinal. Spicules elongated, gubernaculum without apophysis. Preanal sup- plements papilloid. Type genus: Enchilidium Nordman, 1840 (nom. nov. pro Enchelidium Ehrenb., 1836).
Other genera— Calyptronema Marion, 1870 Conistomella Schuur-Stekh., 1942 with two subgenera— Enchilidiella Allgen, 1954 Calyptronema s. str. Polygastrophora de Man, 1922 (syn. Catalaimus Cobb, 1920 (syn. Polygastrophorella Schuur.- Rhinoplostoma AlIgen, 1929) Stekh., 1935) Dilaimus Filipjev, 1927 Symplocostoma Bastian, 1865 (syn. Bradystoma Schuur.-Stekh., Symplocostomella Micol., & Kreis, 1943) 1930
Superfamily TRIPYLOIDEA Chitwood, 1937
Enoplina. Cuticle of head not duplicate; dorsal and at least two of the subventral oesophageal gland cells discharge anteriorly to the nerve ring (the situation in Cryptonchus is not clear). Supplements one or more, often papilloid. Habitat — marine, brackish, or freshwater, and soil. Type genus : Tripyla Bastian, 1865.
Family TRIPYLIDAE Oerly, 1880
Tripyloidea. Dorsal and two subventral glands opening in stomatal region. Stomatal walls not heavily sclerotised, stoma either funnel-shaped, or a slender tube with an inconspicuous median dorsal tooth; oesophago- intestinal valve large. Spicules almost straight, gubernaculum present; sup- plements three or more; caudal glands present. Type genus: Tripyla Bastian, 1865. (syn. Trischistoma Cobb, 1913). Other genus: T obrilus Andrassy, 1959 (nom. nov. pro Trilobus Bastian, 1865 preocc.).
Family IRONIDAE de Man, 1876
Tripyloidea. Dorsal and subventral glands open near stoma; stoma well developed, heavily sclerotised, cylindrical; with or without setae; amphids pocket-like; one preanal seta present in some males; gubernaculum present. Type genus: Ironus Bastian, 1865.
Subfamily IRoNINAE Micol., 1922
Ironidae. With three or more teeth at anterior end of stoma; cephalic setae sometimes present; oesophago-intestinal valve small. Type genus: Ironus Bastian, 1865 (syn. Cephalonema Cobb, 1893). 134 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
Other genera— Conilia Gerlach, 1954 Syringolaimus de Man, 1889 Dolicholaimus de Man, 1888 Thalassironus de Man, 1889 Ironella Cobb, 1920 Trissonchulus Cobb, 1920 Parironus Micol., 1930
Subfamily CRYPTONCHINAE Chitwood, 1937 Ironidae. With one or two small teeth at the base of the stoma; no cephalic setae. Fresh water forms. Type genus: Cryptonchus Cobb, 1913 (syn. Ditlevsenia Micol., 1925).
Suborder ALAIMINA n. suborder Enoplida. Stoma vestigial, unarmed; amphids with crescentic apertures (Amphidelus), or minute, pore-like (Alaimus), commonly placed far back from lip region. Oesophagus dorylaimoid, enlarged only in terminal third. No definite prerectum. Testis single, adanal supplements absent, spicules tripyloid, no gubernaculum. Type genus: Alaimus de Man, 1880.
Family ALAIMIDAE Micol., 1922 Alaimina defined as above. Type genus : Alaimus de Man, 1880. Other genus: Amphidelus Thorne, 1939 Doubtful genus: Adorns Thorne, 1939
Suborder DORYLAIMINA Enoplida. Setae absent. All oesophageal gland duct orifices posterior to nerve ring; oesophageal glands uninucleate, contained within the wall of the oesophagus; oesophagus cylindroid (Mononchoidea), or basically con- sisting of a slender anterior part and an expanded posterior part, typically without valves, rarely bi-bulbar (Nygolaimellinae). Oesphagus never de- generate. Axial stylet or mural tooth or teeth present. Males with ventro- median supplements and two spicules. Caudal glands present in Monon- choidea only. Excretory pore generally absent or rudimentary except in Diphtherophoroidea. Mostly free-living in soil or fresh water, rarely marine (some Dorylaiminae) or plant parasitic (some Tylencholaiminae and Diphtherophoroidea).
Superfamily MONONCHOIDEA n. superfam. Dorylaimina. Oesophagus cylindroid, widening slightly from anterior to posterior end, one dorsal and four subventral, uninucleate oesophageal gland cells. Stoma sclerotised bearing a mural tooth or teeth. Caudal glands typically present. Type genus: Mononchus Bastian, 1865.
1961] CLARK - ENOPLIDA (NEMATODA) 135
Family MONONCHIDAE Chitwood, 1937 Mononchoidea. Stoma large, barrel- or cup-shaped, heavily sclerotised, bearing an immovable dorsal tooth with or without subventral teeth, and/or denticles. Amphids small, apertures slit-like. Gubernaculum present, com- plex lateral accessory pieces commonly present. Caudal glands usually present. Predacious nematodes free-living in soil or freshwater. Type genus: Mononchus Bastian, 1865.
Other genera— Anatonchus (Cobb, 1916) de Con- judonchuhts Andrassy, 1958 inck, 1939 Mylonchulus (Cobb, 1916) Pennak, Brachonchulus Andrassy, 1958 1953 Cobbonchus Andrassy, 1958 Miconchus Andrissy, 1958 Granonchulus Andrassy, 1958 Prionchulus (Cobb, 1916) Chitw. Iotonchus (Cobb, 1916) Altherr, Chitw., 1937 1950 Sporonchulus (Cobb, 1916) Pen- nak, 1953
Family BATHYODONTIDAE n. fam.
Mononchoidea. No setae. Stoma cylindrical, narrow, composed of anterior and posterior sets of three abutting plates (as in Mononchus), the anterior ones more heavily sclerotised than the posterior ones. The posterior elements, or the posterior limit of the anterior ones bearing a single tooth. Tooth left subventral in Miraliamus and Bath yodontus, and reputedly dorsal in Oionchus. Amphids cup-shaped, small. Ovaries single or paired, reflexed; tail short, rounded; caudal glands and terminal duct present. Only females known. Free-living in soil. Type genus: Bathyodontus Field- ing, 1950.
Other genera—
Mirolaimus Andrassy, 1956 Oionchus Cobb, 1913
Remarks. This new family is erected for the reception of genera previously assigned to the Nygolaiminae. They differ from other genera in that sub- family in the form of the oesophagus and the presence of caudal glands and duct. Observations on living Mirolaimus confirm that the caudal gland acts as an adhesive organ. In en face view the similarity of Mirolaimus and the mononchids is remarkable. Oionchus alone possesses the glands at the oesphago-intestinal junction which are also found in the Nygolaims. There are indications that the Bathyodontidae may represent a transitional group between the Mononchoidea and the Dorylaimoidea, and that their kinship lies with the Nygolaimidae rather than with the Dorylaimidae. Knowledge of the males is desirable before this line of argument is pursued. Eno- plochilus Kreis, 1932, once thought to be close to Oionchus is not placed in this classification. It may belong near the Eurystominae on the evidence of the reniform amphid, but it has nothing to do with the Dorylaimina. 136 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
Superfamily DORYLAIMOIDEA Thorne, 1934
Dorylaimina. Oesophagus basically consisting of a slender anterior part and an expanded posterior part; cephalic papillae in two rings, 6 in the inner and 10 in the outer; amphid apertures posterior to the cephalic papillae. Amphids stirrup-shaped or pouch-like with slit-like or ellipsoidal apertures. Stoma armed with an axial spear with a dorsal aperture, or a mural tooth. Lateral pores and prerectum present. Supplements consisting of a ventro- median series and an adanal pair. Testes two. No caudal glands.
Family DORYLAIMIDAE de Man, 1876 Dorylaimoidea. Polymyarian. Amphids with obscure slit-like apertures. Stoma with an axial spear; oesophagus enlarged in posterior third or more, enlarged part not surrounded by a spiral sheath of connective tissue (a non- spiral sheath in Drepanodorus striatus (Krall, 1958) ). Cuticle generally with minute transverse striae, sometimes with wing-like longitudinal striae over the whole body (certain species of Dorylaimus and Actinolaimus). Spicules with lateral guiding pieces; gubernaculum absent. Type genus : Dorylaimus Dujardin, 1845.
Subfamily DORYLAMINAE Filipjev, 1918 Dorylaimidae. Spear axial, spear or extensions not greatly elongated, with- out basal knobs, flanges, or tripartite extensions. Ovaries one or two. (Only species with sheath of connective tissue about enlarged part of oesophagus Drepanodorus striatus (Krall, 1958) which is characterised by also having the spear aperture longer than half the spear length.) Type genus: Dory- laimus Dujardin, 1845.
Other genera— Amphidorylaimus Andrassy, 1959 Lordellonema Andrassy, 1960 Aporcelaimus Thorne & Swanger, Mesodorylaimus Andrassy, 1959 1936 Meylonema Andrassy, 1950 Chrysonema Thorne, 1929 Prodorylaimus Andrassy, 1959 Discolaimium Thorne, 1939 Pun gentus Thorne & Swanger, 1936 Discolaimus Cobb, 1919 Thornia Meyl, 1954 Drepanodorus Altherr, 1954 T horneella Andrissy, 1960 (n. syn. Paraxonchium Krall, 1958) Thornema Andrassy, 1959 Eudorylaimus Andrassy, 1959 Wittoldinema Brzeski, 1960 Labronema Thorne, 1939
Remarks. The inclusion of Paraxonchium striatum Krall = Drepanodorus striatus (Krall, 1958) n. syn. in the Dorylaiminae is problematical. In conjunction with Dr J. B. Goodey it has been decided that because this species is so similar to other species referred to Drepanodorus, apart from the presence of the sheath about the expanded part of the oesophagus that it is best included here. Authors of the other species of Drepanodorus (Altherr, 1954 and Andrkssy, 1956) did not record any such sheath. 1961] CLARK - ENOPLIDA (NEMATODA) 137
Subfamily TYLENCHOLAIMINAE Filipjev, 1934
(including Longidorinae Thorne, 1935) Dorylaimidae. Spear short with knobbed or flanged spear extensions, or greatly elongated with long, rod-like, or flanged extensions. Ovaries one or two. Tail similar in both sexes where known, except Miranema. Type genus : Tylencholaimus de Man, 1876.
Other genera— Discomyctus Thorne, 1939 Miranema Thorne, 1939 Enchodelus Thorne, 1939 Utahnema Thorne, 1939 Longidorella Thorne, 1939 Xiphinema Cobb, 1913 Longidorus Micol., 1922 Xiphinemella Loos, 1950 (syn. Taprobanus Loos, 1949)
Remarks. Tylencholaimus bryophilus Imamura, 1931 was referred by Thorne, 1939 to Doryllium Cobb, 1920. It does not conform with Thorne's diagnosis of the genus because of its prodelphic ovary, and the large number of ventro-median supplements. The fine spear with its minute knobs con- trasts strikingly with the other species referred to the genus. The shape of the oesophagus as figured by Imamura (1931) appears leptonchid, but may be interpreted as a further development of the type of oesophagus known in Tylencholaimus nikkoensis Kaburaki & Imamura, 1933 which was re- tained within the Tylencholaiminae by Thorne. Whilst the systematic posi- tion of T. bryophilus is difficult to determine I prefer on the basis of the spear, ovaries, and supplements to place this species once more in the genus Tylencholaimus de Man, 1876. It may be noted that the original figures of T. nikkoensis and T. kirifuri Kaburaki & Imamura, 1933 differ in a number of important diagnostic features from the figures in Thorne, 1939.
Subfamily ACTINOLAIMINAE Thorne, 1939 Dorylaimidae. Walls of stoma partially or completely sclerotised, fre- quently bearing onchia or denticles. Supplements sometimes grouped intd fascicles. Type genus : Actinolaimus Cobb, 1913, (= Brasilaimus Lordello & Zamith, 1957 n. syn.).
Other genera— Actinolaimoides Meyl, 1957 Mylodiscus Thorne, 1939 Antholaimus Cobb, 1913 Paractinolaimus Meyl, 1957 Carcharolaimus Thorne, 1939 Trachypleurosum Andrassy, 1959 nom. Metactinolaimus Meyl, 1957 nov. pro. Trachypleura Thorne, 1939, preocc.
Remarks. Brasilaimus Lordello & Zamith, 1957 is indistinguishable from Actinolaimus Cobb, 1913 on the basis of the information supplied in the generic diagnosis, or in the description and figures of the type species
138 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
B. subaquilus L. & Z., 1957. Brasilaimus is therefore synonymised with Actinolaimus Cobb, 1913. B. subaquilus becomes Actinolaimus subaquilus (Lordello & Zamith, 1957) n. comb.
Family OPAILAIMIDAE Kirjanova, 1951 Dorylaimoidea. Amphids and sensillae very large, expanded; posterior half of the oesophagus surrounded by a "cuticular" sheath. Spear long fine, delicate, unlike that of the Dorylaimidae. Type genus: Opailamus Kirjan- ova, 1951.
Other genus: Ottolaimus Kirjanova, 1951.
Remarks: The above diagnosis is a free paraphrasing of Kirjanova (1951). The exact status of this family is rather doubtful. Neither of the two species referred to it is adequately described or figured for species which reputedly possess so many outstanding characters. The arrangement of the spear, guiding ring, and amphid apertures of Opailaimus appears most unusual. Ottolaimus could well be based on a moulting specimen of Discolaimus. Both genera urgently need careful study.
Family BELONDIRIDAE Thorne, 1939 Dorylaimoidea. Polymyarian. Spear axial, small, often slightly arcuate in lateral view, dorsal aperture never distinctly longer than half spear length; spear extensions in two obscurely separated sections which bear broad flanges. Basal enlargement of oesophagus very variable in size, always surrounded by a sheath of spiral connective tissue. Ovaries paired or single; anterior ovary usually vestigial or absent. Supplements an adanal pair and a ventro-median series. Lateral guiding pieces present except in Dory- laimellus. Tails of both sexes similar where known. Type genus: Belondira Thorne, 1939.
Other genera— Axonchium Cobb, 1920 Oxydirus Thorne, 1939 Dorylaimellus Cobb, 1913 Swangeria Thorne, 1939 (syn. Pungentoides Altherr, 1950)
Remarks. See under Nygolaimidae.
Family NYGOLAIMIDAE Thorne, 1939 n. grad. Dorylaimoidea. Polymyarian. Spear a left subventral mural tooth set in an eversible stoma. Oesophagus usually expanded in basal half or more, rarely bi-bulbar (Nygolaimellinae) ; with or without a spiral sheath of connective tissue about expanded part. Three glandular bodies present at oesophago-intestinal junction. Ovaries paired or single, reflexed. Lateral guiding pieces and gubernac-uluin present in all known males. Type genus: Nygolaimus Cobb, 1913. 1961] CLARK — ENOPLIDA (NEMATODA) 139
Remarks. I have somewhat changed the diagnoses of the families Belondi- ridae and Nygolaimidae, and the emphasis that Thorne placed on certain characters. The Nygolaimidae are characterised by the presence of a ventro- lateral mural tooth, with or without a spiral oesophageal sheath, whereas the Belondiridae are characterised by the presence of an axial spear and the spiral sheath of connective tissue about the base of the oesophagus. It is largely on these grounds that I have removed the genera Nygellus and Nygolaimellus from the Belondiridae and assigned them to the Nygolai- midae. It should also be noted that both genera possess the three glandular bodies at the oesophago-intestinal junction, a feature found in the Nygo- laimidae but not in the Belondiridae. Thorne may have been influenced in placing Nygellus with the Belondirids by the single posterior ovary in N. clavatus Thorne, but N. symnzetricus Williams, 1958 shows that this character is not constant within the genus. See also remarks on the Bathyodontidae.
Subfamily NYGOLAIMINAE Thorne, 1939 Nygolaimidae. Oesophagus unibulbar, with or without a spiral sheath about oesophagus base. Type genus: Nygolaimus Cobb, 1913.
Other genera— Heterodorus Altherr, 1952 Sectonema Thorne, 1930 Nygellus Thorne, 1939
Subfamily NYGOLAIMELLINAE n. subfam. Nygolaimidae. Oesophagus bibulbar, with a sheath about posterior part of oesophagus. Type genus : Nygolaimellus Loos, 1949.
Family LEPTONCHIDAE Thorne, 1935 Dorylaimoidea. Meromyarian. Spear axial, basal extensions well developed, or bearing basal knobs or flanges. Amphids large, stirrup shaped, aperture rather narrow in some Tylencholaimellus spp. Oesophagus slender with a short expanded basal region (rarely as much as one third of oesophageal length in some Dorylainzoides), which may be set off by a marked con- striction. Lateral series of pores in two lines. Prerectum present. Males where known with lateral guiding pieces; no gubernaculum. Type genus: Leptonchus Cobb, 1920.
Other genera—. Dorylaimoides Thorne & Sw., 1936 Proleptonchus Lordello, 1953 Doryllium Cobb, 1920 Tylencholaimellus Cobb, 1915
Remarks. I am not convinced that the Leptonchidae form a coherent natural group, nor that these meromyarian types naturally belong within 140 NEW ZEALAND JOURNAL OF SCIENCE [MAR. the Dorylaimoidea which are essentially polymyarian. Opinion is divided on the value of this feature as a taxonomic criterion. When more forms are known it may be possible to define and subdivide the group with more certainty. In the meantime I have removed the Campydorinae from this family.
Family CAMPYDORIDAE Thorne, 1935 n. grad. Emend.
Dorylaimoidea. Meromyarian. Oesophagus slender in anterior four-fifths, small basal bulb, often set off by a marked constriction, with a triquetrous valvular chamber. Amphids stirrup-shaped; spear axial, with or without flanged basal extensions or a dorsal mural tooth. Ovary single, either pro- or opistho-delphic. Prerectum and excretory pore present or absent. Type genus: Campydora Cobb, 1920.
Other genera— Aulolaimoides Micol., 1914 Tyleptus Thorne, 1939
Remarks. This family as it now stands is a "taxonomic expediency". Its chief purpose is to gather together the three genera that have a valve-like chamber in a small posterior oesophageal bulb, and which do not fit into any other family. As more species and genera with this character become known it will become necessary to subdivide it, a practice which has little to commend it at the present time.
Superfamily DIPHTHEROPHOROIDEA n. superfam.
Dorylaimina. Meromyarian. Spear short, stout, complex, or long, arcuate, attenuated, only tip moulted. Amphid apertures ellipsoidal. Anatomical details generally obscured by abundant granules. Oesophagus with a pyri- form to elongate conoid basal bulb. Prerectum absent; testis one; ventro- median supplements present, adanal pair absent; gubernaculum present. Type genus: Diphtherophora de Man, 1880.
Family DIPHTHEROPHORIDAE Thorne, 1935 Emend
Diphtherophoroidea. Spear with basal knobs, stout, posteriorly of complex archlike structure in anterior part of dorsal sector, ventral sector apparently not fused to dorsal sector posteriorly. Guiding apparatus of spear a com- plicated structure of plates and rods of which an inverted V-shaped piece is often the most conspicuous. Supplements often reduced or vestigial. Type genus: Diphtherophora de Man, 1880. 1961] CLARK - ENOPLIDA (NEMATODA) 141
Other genera— Brachynemella Cobb, 1933 Triplonchium Cobb, 1920 (syn. Brachynema Cobb, 1893 pre- Tylolaimophorus de Man, 1880 occ.)
Family TRICHODORIDAE Thorne, 1935 n. grad.
Diphtherophoroidea. Spear strictly a dorsal tooth, long, attenuated, arcuate, without basal knobs (often described as tripartite in the middle region but this is a misinterpretation — see below). Ovaries paired or single, reflexed when paired; males with or without caudal alae; spicules straight or nearly so. Tail length not more than one anal-body-width. Type genus: Tricho- dorus Cobb, 1913.
Remarks. Allen (1957) has monographed this group and has figured the cross section of the "tripartite" part of the spear as U-shaped. He has in- formed me (in litt.) that the tripartite appearance is due to the greater passage of light through the centre of the spear when it is viewed laterally.
Suborder TRICHOSYRINGINA Ward, 1917 Enoplida. Setae absent; oesophageal glands forming a stichosome outside the contour of the oesophagus. Amphids pocket-like (some Mermithoidea) to pore-like. Parasitic at some stage of the life history in terrestrial or freshwater arthropods (Mermithoidea) or in vertebrates (Trichuroidea). Type genus : Trichuris Roederer, 1761.
Superfamily MERMITHOIDEA Wiilker, 1924 Trichosyringina. Amphids modified pocket-like to pore-like; intestine extending anterior to base of oesophagus, usually without a lumen. Male with one or two spicules, usually two testes. Female reproductive system highly developed, usually with two ovaries and tubular vagina. Eggs modi- fied, but not operculate. Bursa present in some Eurymermis. Type genus : Mermis Dujardin, 1842.
Family MERMITHIDAE Braun, 1883 Mermithoidea. Oesophagus not dorylaimoid in larval stages; larvae with an axial spear. Adults long slender worms with a smooth cuticle. Adult intestine replaced by trophosome or pseudo-intestine. Anus non functional. Larvae parasitic in freshwater and terrestrial arthropods. Adults free-living. Type genus: Mermis Dujardin, 1842. 142 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
The following genera have been erected— Agamermis Cobb, Steiner & Chris- Heydonius Taylor, 1935 tie, 1923 Hydronzermis Corti, 1902 Agarnornermis Stiles, 1903 Isomern2is Coman, 1953 Allomermis Steiner, 1924 Limnomermis Daday, 1911 Amphidomermis Filipjev, 1934 Megalomernzis Muller, 1931 Amphimermis Kaburaki & Ima- Mesomermis Daday, 1911 mura, 1932 Nanonzermis Cobb, 1924 Bathymermis Daday, 1911 Neomermis Linstow, 1904 ? BolbinMm Cobb, 1920 (syn. Octornermis Steiner, 1929) Complexomermis Filipjev, 1934 Paramermis Linstow, 1898 Eomermis Steiner, 1925 Phreatomermis Coman, 1953 Eumermis Daday, 1911 Psammomermis Polzhentsev, 1941 Eurymermis Muller, 1931 Pseudomermis de Man, 1903 Filipjevimermis Polozhentsev & Art- Skrjabinomermis Polozhentsev, 1952 yukhovsky, 1958 Tetramermis Steiner, 1925 Gastromermis Micol., 1925 Tunicamermis Schuur-Stekh., Mawson, Gordiomermis Heinze, 1934 & Couturier, 1955 Hexamermis Steiner, 1934
Remarks. The above list of generic names was supplied by Dr H. E. Welch, who has in preparation a critical revision of the Mermithidae which may result in the synonymisation or rejection of some of the generic names listed above.
Family TETRADONEMATIDAE Cobb, 1919 Mermithoidea. Oesophagus dorylaimoid in larvae. All stages of life his- tory may be found in insects; no rectum or anus in adults; males with one spicule, with or without supplements. Type genus: Tetradonema Cobb, 1919.
Other genera— Aproctonerna Keilin, 1917 Mermithonema Goodey, 1941
Superfamily TRICHUROIDEA Railliet, 1915 syn. Trichocephalata Skrjabin & Schultz, 1928 Trichosyringina. Amphids pore like; a spear present in larvae, rarely present in adults; intestine not extending anterior to base of oesophagus, lumen well developed, rarely terminating blindly (Cystoopsidae). Males with one testis and one or no spicules. Female with tubular vagina, one ovary; eggs typically operculate. Parasites of vertebrates in adult stages. Life history direct or indirect. Type genus : Trichuris Roederer, 1761.
Remarks. I have retained the more familiar name for this superfamily for the present. Although Leiper (1926) pointed out that Trichuris Roederer, 1761 is not available under the Rules, and that the correct name should be 1961] CLARK - ENOPLIDA (NEMATODA) 143
Trichocephalus Goeze, 1882, most workers have been loath to adopt it. Under the Copenhagen Decisions on zoological nomenclature there is no longer any need to change family names which have been based on junior synonyms. The situation is not clear in this case as Trichuris is not strictly a synonym as it has never been legally available.
Family TRICHURIDAE Railliet, 1915 Trichuroidea. Oviparous, stichosome one row of stichocytes. Males with one spicule. Type genus: Trichuris Roederer, 1761.
Subfamily TRICHURINAE Ransom, 1911 Trichuridae. Posterior part of body distinctly wider than anterior part; oesophageal region much longer than rest of body. Type genus: Trichuris Roederer, 1761 (syn. Trichocephalus Goeze, 1882).
Subfamily CAPILLARIINAE Railliet, 1915 Trichuridae. Posterior part of body not distinctly wider than anterior part; oesophageal region not distinctly longer than rest of body. Type genus: Capillaria Zeder, 1800 (syn. Aonchotheca Lopez-Neyra, 1947, Capillo- strongyloides Freitas & Lent, 1935).
Other genera— Eucoleus Dujardin, 1845 Skrjabinocapillaria Skarbilovitch, 1946 Hepaticola Hall, 1916 Thominx Dujardin, 1845 (syn. Echinocoleus Lopez-Neyra, 1947)
Family TRICHOSOMOIDIDAE York & Maplestone, 1926 Trichuroidea. Oesophageal region roughly equal to, or shorter than remainder of body; spear present or absent in adults. Males without spicules or copulatory sheath; either much smaller than female and para- sitic within uterus or vagina, or non-parasitic and equal in size to female. Females oviparous or ovoviviparous. Type genus: Trichosornoides Railliet, 1895.
Subfamily TRICHOSOMOIDINAE Hall, 1916 Trichosomoididae. Oesophagus about equal to rest of body. Spear absent in adults. Males minute, parasitic within uterus of female. Type genus: Trichosomoides Railliet, 1895.
Other genus— Trichuroides Ricci, 1949. 144 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
Subfamily ANATRICHOSOMATINAE Smith & Chitw., 1954 Trichosomoididae. Oesophagus one-third to one-sixth of body-length. Males not parasitic in female, size equal to or larger than females. Adults with spears. Parasites of monkeys. Type genus: Anatrichosoma Smith & Chitwood, 1957. Family TRICHINELLIDAE Ward, 1907 Trichuroidea. Ovoviviparous; stichosome one row of stichocytes ; males not degenerate; without spicules. Vulva in middle of oesophageal region. Oesophagus more than half body length in female, less than half body length in male. Type genus: Trichinella Railliet, 1895 (syn. Trichina Owen, 1835 nec Meigen, 1830).
Family CYSTOOPSIDAE Skrjabin, 1923 Trichuroidea. Oviparous. Stichosome two rows of stichocytes. Males with one spicule. Vulva in oesophageal region. (Only one species which is parasitic in the skin of the Volga sturgeon.) Type genus: Cystoopsis Wagner, 1867. Suborder DIOCTOPHYMATINA Enoplida. Setae absent, but long papillae may be present in larval stages. Oesophageal glands highly polynucleate, branching dichotomously within the contour of the oesophagus, ducts opening anterior to nerve ring. No lips; no spear in adults; oesophagus cylindroid, reproductive system single in both sexes. Males with one spicule in caudal sucker. Eggs operculate. Adults parasites of vertebrates.
Family DIOCTOPHYMATIDAE Railliet, 1915 Dioctophymatina. Muscular cephalic sucker absent. Type genus: Diocto- phyme Collet-Meygret, 1802.
Subfamily DIOCTOPHYMATINAE Cast. & Chambers, 1910 Dioctophymatidae. Very large nematodes, females up to one metre long, males one-third of this. Vulva in anterior part of body. Adults parasitic in mammals. Type genus: Dioctophyme Collet-Meygret, 1802. Other genus : Mirandonema Kreis, 1945.
Subfamily EUSTRONGYLINAE Chitw. & Chitw., 1937 Dioctophymatidae. Moderate to large size, cuticle coarsely striated towards extremities, with or without spines. Vulva near anus. Adults parasitic in birds. Type genus: Eustrongylides Jagerskitild, 1909. Other genus: Hystrichis Dujardin, 1845. 1961] CLARK - ENOPLIDA (NEMATODA) 145
Family SOBOLIPHYMATIDAE Petrov, 1930
Dioctophymatina. With large muscular cephalic sucker. Females oviparous, with vulva near anus. Adults parasitic in carnivores and fish. Type genus: Soboliphyme Petrov, 1930.
KEY TO FAMILIES AND SUBFAMILIES OF THE ENOPLIDA
Taxonomic keys are attempts at finding short cuts, and like other short cuts they have their dangers. All identifications, at even the higher levels, must be checked against full descriptions and figures. In this key items in italics are spot characters, if they can be determined with certainty the remainder of the couplet may be ignored. References in brackets refer to published keys to genera.
1. Oesophageal glands within contour of oesophagus 9 Oesophageal glands present as a stichosome outside oesophageal contour TRICHOSYRINGINA 2
2. Intestine extending anterior to base of oesophagus, usually without a lumen MERMITHOIDEA 3 Intestine not extending anterior to base of oeso- phagus, lumen well developed TRICHUROIDEA 4
3. Oesophagus dorylaimoid in larval stages; adults and larvae found in insects. Males with one spicule TETRADONE MATIDAE Oesophagus not dorylaimoid in larval stages; only larvae parasitic in terrestrial and freshwater arthro- pods; males with one or two spicules MERMITHIDAE
4. Stichosome one row of stichocytes 5 Stichosome two rows of stichocytes CYSTOOPSIDAE
5. Males degenerate living within the uterus or vagina of the female, or lacking spicules and couplatory sheath 6 Males not degenerate, with one spicule 8
6. Males degenerate, living within female uterus or vagina TRICHOSOMOIDINAE Males not degenerate, not living within female 7
7. Adults with spear, vulva near oesophago•intestinal junction ANATRICHOSOMATINAE Adults without spear, vulva in middle of oesophageal region TRICHINELLIDAE
8. Oesophageal region extremely slender, longer than remainder of body TRICHURINAE Oesophageal region shorter than rest of body and not remarkably slender CAPILLARIINAE
9. Very large nematodes, adults parasitic in vertebrates; males with caudal sucker and one spicule; eggs oper- culate DIOCTOPHYMATINA 10 Not very large; not parasitic in vertebrates, males without caudal sucker; eggs not operculate 12 Sig. 10 146 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
10. With muscular cephalic sucker SOBOLIPHYMATIDAE Without muscular cephalic sucker DIOCTOPHYMATIDAE 11
11. Vulva in anterior part of body DIOCTOPHYMATINAE Vulva in posterior part of body EUSTRONGYLIDINAE 12. Stoma vestigial, without spear or teeth, cephalic setae absent, oesophagus dorylaimoid, males without adanal supplements or gubernaculum (Thorne, 1939) ALAIMIDAE Not as above 13 13. All oesophageal gland ducts posterior to nerve ring, no cephalic setae, oesophagus cylindroid, dorylaimoid or bi-bulbar; axial spear or mural tooth or teeth present, rarely marine — some Dorylaiminae. Caudal glands present in Mononchoidea only DORYLAIMINA 14 Some or all oesophageal gland ducts anterior to nerve ring; usually with cephalic setae, oesophagus cylin- droid, crenate, conoid or multibulbar. Caudal glands usually present ENOP LINA 28 14. Oesophagus cylindroid MONONCHOIDEA 15 Oesophagus dorylaimoid, conoid, or bi-bulbar 16 15. Stoma heavily sclerotised, cup- or barrel-shaped; armed with one or three teeth, tail conoid, arcuate, or filiform (Andrassy, 1958) MONONCHIDAE Stoma moderately sclerotised; elongate, narrow; tail short, rounded, not conoid or filiform BATHYODONTIDAE 16. Spear short, stout with dorsal and ventral elements apparently separate posteriorly, or long, slender arcu- ate without dorsal aperture; prerectum, lateral pores, and adanal supplements absent; one testis; excretory pore usually visible; anus often almost terminal DIPHTHEROPHOROIDEA 17 Spear a hollow tube with an oblique dorsal aperture (aperture may be absent when spear is mural), often with variously developed spear extensions. Testes two; adanal supplements, lateral pores, and usually prerectum present. Excretory pore absent or rudi- mentary DORYLAIMOIDEA 18 17. Spear short, complex, with basal knobs; spear guid- ing apparatus of sclerotised plates and rods (Thorne, 1939) DIPIITHEROPHORIDAE Spear long, arcuate, tapering towards ends, without basal knobs; obscure non-sclerotised guiding ring present (Allen, 1957) TRICHODORIDAE 18. Oesophageal bulb small, with a triquetrous valvular chamber CAMPYDORIDAE Oesophageal bulb without a triquetrous valvular chamber 19
19. Spear mural NYGOLAIMIDAE 20 Spear axial 21 20. Oesophagus bi-bulbar NYGOLAIMELLINAE Oesophagus mono-bulbar (dorylaimoid) NYGOLAIMINAE 21. Posterior part of oesophagus with a spiral sheath of connective tissue; anterior ovary usually vestigial or absent (if spear aperture is more than half spear length c.f. Drepanodorus Dorylaiminae) BELONDIRIDAE Oesophagus without a spiral sheath 22 1961] CLARK - ENOPLIDA (NEMATODA) 147
22. Spear extensions bearing knobs 23 Spear extensions not bearing knobs, but may bear flanges 24 23. Males with adanal and one ventromedian supplement, spear knobs moderate to large, spear with dorsal thickening. Females with posterior ovary only, anterior uterus greatly reduced or absent part of LEPTONCHIDAE Males with adanal and three or more ventromedian supplements; spear knobs small, spear not thickened dorsally. Females with only anterior or paired ovaries (single and posterior only in Tylencholaimus zee- landicus de Man, 1876) part of TYLENCHOLAIMINAE 24. Oesophagus enlarged in distal third or more 25 Oesophagus enlarged in less than distal third; pos- terior bulb often pyriform or set off by marked constriction remainder of LEPTONCHIDAE 25. Spear short and stout with oblique aperture, or if slender spear length greater than three times width of lip region. Spear often with flanges. Posterior half of oesophagus without cuticular sheath DORYLAIMIDAE 26 Spear slender tapering uniformly to tip, length less than three times width of lip region; spear without knobs or flanges. With amphids very large, or with two anteriorly projecting "ears" on head. Posterior half of oesophagus surrounded by a "cuticular" sheath OPAILAIMIDAE 26. Stomatal region heavily sclerotised, often dentate ACTINOLAIMINAE Stomatal region not heavily sclerotised; never dentate 27 27. Spear and spear extension simple, short or of moder- ate length, never bearing flanges, etc (Andrassy, 1959) DORYLAIMINAE Spear and or extensions greatly attenuated, or spear of moderate length with flanged extensions TYLENCHOLAIMINAE 28. All oesophageal gland ducts opening in stomatal region anterior to nerve ring. Cuticle of head dupli- cate; supplements 0, 1, or 2 ENOPLOIDEA 28 Dorsal and two subventral oesophageal glands open- ing anterior to nerve ring. Cuticle of head not dupli- cate; supplements one or more TRIPYLOIDEA 37 29. Vagina opening into cloaca, no external vulva LAURATONEMATIDAE Vulva normal, external; vagina not discharging into cloaca 30 30. Stomatorhabdions poorly sclerotised; without distinct stomatal capsule, stoma surrounded by oesophageal tissue, or stoma absent 31 Stomatorhabdions heavily sclerotised, stoma some- what capsuliform; only posterior part surrounded by oesophageal tissue ONCHOLAIMIDAE 35 31. Stoma absent, supplement papilloid males of ENCHILIDIINAE Stoma present supplement(s) tuboid or absent ENOPLIDAE 32 32. Stoma with three bifurcate mandibles ENOPLINAE Stoma without three bifurcate mandibles 33 33. Posterior part of oesophagus crenate in outline, vesi- culate, musculature reduced (Wieser, 1953a) PHANODERMATINAE Posterior part of oesophagus not crenate in outline, never vesiculate 34
148 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
34. Supplements absent; oesophagus conoid, oesophageal musculature weak; 6 + 4 setae in external circle (Wieser, 1953a) OXYSTOMATINAE Supplements one or two, tuboid; oesophagus usually cylindroid, rarely conoid; posterior oesophageal musculature well developed. Ten setae in external circle (Wieser, 1953b) LEPTOSOMATINAE 35. Oesophagus cylindroid, never crenate; supplements absent or pedunculate (Wieser, 1953a) ONCHOLAIMINAE Oesophagus conoid, crenate or multibulbar; supple- ments papilloid, cup-like, or rarely absent 36 36. With sexual dimorphism of stoma; males without a stoma. Female stoma generally narrow, divided by a number of transverse rings into several chambers (sometimes rings faint giving the impression of two chambers in Calyptronema). Teeth slender, needle- like, base narrow. Spicules elongate, gubernaculum without apophysis; supplements papilloid (Wieser, 1953a) ENCHILIDIINAE Without sexual dimorphism of stoma; stoma large, divided by one • or more bands, rings, or rows of denticles into two chambers. Tooth broad with large base. Spicules short, arcuate, gubernaculum usually with a dorsal apophysis; supplements sclerotised, cup-like when present (Wieser, 1953a) EURYSTOMINAE 37. Stoma walls not heavily sclerotised; stoma either fun- nel-shaped or a very slender tube with an incon- spicuous dorsal tooth. Tooth or teeth in median part of stoma. Spicules almost straight TRIPYLIDAE Stoma walls strongly sclerotised, stoma elongate, teeth at anterior or posterior end of stoma. Spicules usually arcuate IRONIDAE 38 38. Teeth at anterior end of stoma, commonly with cephalic setae IRONINAE Teeth at posterior end of stoma, never with cephalic setae CRYPTONCHINAE
ACKNOWLEDGMENTS As is inevitable in a task such as this I have drawn heavily on the work of many other workers and I wish to acknowledge my indebtedness to them. I have sought advice from many workers especially Dr J. B. Goodey, Dr H. E. Welch, Prof. M. W. Allen, and Prof. R. T. Leiper. I wish to thank Dr Goodey and Prof. Leiper for reading the manuscript, but the responsibility for the conclusions, errors, and shortcomings of the proposed scheme is mine alone.
REFERENCES
ALLEN, M. W. 1957: A Review of the Nematode Genus Trichodorus with Descrip- tions of Ten New Species. Nematologica, 2 (1): 32-62. ANDRASSY, I. 1958: Uber das System der Mononchiden (Mononchidae, Chitwood, 1937; Nematoda) Ann. hist.-nat. Alas, hung. n.s. 9, 50: 151-71. 1959: Taxonomische Ubersicht der Dorylaimen (Nemotoda) 1, Act. zool. Acad. Sci. hung. 5: 191-240. 1961] CLARK - ENOPLIDA (NEMATODA) 149
CHITWOOD, B. G. 1937: A Revised Classification of the Nematoda, in "Papers in Helminthology, 30 Year Jubileum K. I. Skrjabin," Moscow, pp. 69-80. CHITWOOD, B. G.; CHITWOOD, M. B. 1937: "An Introduction to Nematology" Sec- tion 1, Part 1, Monumental Printing Co. Baltimore. 53 pp. 1950: "An Introduction to Nematology" (2nd edit.) Chitwood, Baltimore. 213 pp. CLARK, W. C. 1960a: The Oesophago-intestinal Junction in the Mononchidae (Eno- plida, Nematoda), Nematologica 5, (3): 178-83. 1960b: Redescriptions of Mononchus truncatus Bastian, M. papillatus Bastian, and Prionchulus muscorum (Dujardin) (Enoplida: Nematoda), Nematologica 5, (3): 184-98. 1960c: The Mononchidae (Enoplida: Nematoda) of New Zealand. 1. The Genera Mononchus Bastian and Prionchulus Cobb. Nernatologica 5, (3): 199-214. 1961a: The Mononchidae (Enoplida: Nematoda) of New Zealand. 2. The genus lotonchus (Cobb, 1916) Altherr, 1950. Nematologica 5, (4): 260-74. 1961b: The Mononchidae (Enoplida: Nematoda) of New Zealand. 3. A review of the genus Cobbonchus Andrassy, 1958, with Descriptions of New Species. Nematologica 5, (4): 275-84. 1961c: The Mononchidae (Enoplida: Nematoda) of New Zealand. 4. The Genus Mylonchulus (Cobb, 1916) Pennak, 1953. Nernatologica (in press). FILIP JEV, I. N. 1934: The Classification of the Free-living Nematodes and Their Relation to the Parasitic Nematodes. Smithson. misc. Coll., 89 (6): 1-63. FULLEBORN, F. 1923: -Ober den "Mundstachel" der Trichotracheliden-Larven und Bemerkungen iiber die jungsten Stadien von Trichocephalus trichiurus. Arch. Schiffs. u. Tropen. Hyg., 27, (11): 413-20. GOODEY, T. 1942: Observations on Mononchus tridentatus, M. brachyuris and other Species of the Genus Mononchus. J. Helminth., 20: 9-24. 1951: "Soil and Freshwater Nematodes", Methuen, London. 390 pp. GOODEY, J. B.; PEACOCK, F. C.; PITCHER, R. S. 1960: A Redescription of Xiphinema diversicaudatum (Micoletzky, 1923 & 1927) Thorne, 1939, and Observations on its Larval Stages. Nernatologica 5, (2) : 127-35. HYMAN, L. H. 1951: "The Invertebrates: Acanthocephala, Aschelminthes, and Ento- procta. The Pseudocoelomate Bilateria, (Vol. 3)", McGraw-Hill, New York, 573 pp. IMAMURA, S. 1931: Nematodes in the Paddy Field, with Notes on their Population before and after Irrigation. J. Coll. Agric. Tokyo, 11 (2): 198-240. KABURAKI, T.; IMAMURA, S: 1933: Descriptions of Two New Soil Nemas in the Nikko District. Proc. imp. Acad. Japan, 9, (3) : 134-6. LEIPER, R. T. 1927: Discussion of the Validity of Certain Generic Names at Present in Use in Medical Helminthology. Coll, Addr. Lond. Sch. Hyg. 3: 484-91. LUKASIAK, J. 1930: Anatomische und Entwicklungsgeschichtliche Untersuchungen an Dioctophyme renale (Goeze, 1782) (Eustrongylus gigas Rud.). Arch. Nauk. biol. 3: 1-99. RAumER, M. 1918: Mitteilungen zur Nematodenkunde. Zool. Jb., (Abt. 2), 40: 441-516. 150 NEW ZEALAND JOURNAL OF SCIENCE [MAR.
SKRJABIN, K. I.; SHIKHOBALOVA, N. P.; SOBOLEV, A. A.; PARAMONOV, A. A.; SUDARI- KOV, V. E. 1954: "[Descriptive Catalogue of Parasitic Nematodes Vol. IV. Camallata, Rhabditata, Tylenchata, Trichocephalata, Dioctophy- mata and a Classification of Parasitic Nematodes under Hosts]". Izdatelstvo Akademii Nauk. S.S.S.R., Moscow, 927 pp. SKRJABIN, K. I.; SHIKHOBALOVA, N. P.; ORLOV, I. V. 1957: "[Principles of Nema- tology, edit. K. I. Skrjabin, Vol. VI. Trichocephalidae and Capillariidae of Animals and Man, and the Diseases caused by them}". Akademia Nauk., S.S.S.R., Moscow, 587 pp. STEINER, G. 1917: 'Ober die Verwandtschaftsverhaltnisse and die Syste:natische stellung der Mermithiden. Zool. An:., 48: 263-7. THORNE, G. 1939: A Monograph of the Nematodes of the Superfamily Dory- laimoidea, Capita zool. 8, (5) : 1-261. WIESER, W. 1953a: Reports of the Lund University Chile Expedition 1948-49. Free-living Marine Nematodes. I. Enoploidea. Acta Unit,. lund., n.s. 49, (6) : 1-155. 1953b: On the Morphology of the Head in the Family Leptosomatidae (Marine Free-living Nematodes). With a Key to all Described Genera. Ark. Zool. (ser. 2) 6 (3): 69-73. WOODHEAD, A. E. 1950: Life History Cycle of the Giant Kidney Worm, Diocto- phyme renale (Nematoda), of Man and many other Mammals. J. Parasit., 69: 21-46. Nemato/ogica 5 (1960): 178183. E. J. Brill, Leiden
3. THE OESOPHAGO-INTESTINAL JUNCTION IN THE MONONCHIDAE (ENOPLIDA, NEMATODA)
BY
W. C. CLARK Rothamsted Experimental Station, Harpenden, Herts, England 1)
1) At present on study leave from Entomology Division, D.S.I.R., Nelson, New Zealand. While examining many species of the Mononchidae it became evident that the structure of the oesophago-intestinal junction in this family has been mis- interpreted. The detailed structure of all the species examined differs from the published figures and descriptions because most workers have worked with fixed material, and also because the oesophago-intestinal junction has not been con- sidered important. In specimens fixed in F.A. 4 : 10 or T.A.F. some of the valve structures described here are often obscure or invisible. For this reason the nema- todes must be studied alive, narcotized, or immediately after "relaxing" with heat. The valve "funnel" (see later) may become obscure within 15-20 minutes of death. A 0.5 per cent aqueous solution of M.S. 222 Sandoz (a soluble salt of a meta-amino-benzoic acid ethyl ester) is a suitable narcotic for mononchs. The oesophago-intestinal valves in the Mononchidae are of two types, for which the terms "tuberculate" and "non-tuberculate" are proposed. In this paper Prion- chulus muscorum (Dujardin) exemplifies the non-tuberculate type, and Anaton- chur tridentatus (de Man) the tuberculate type. The mononch oesophagus was first described by CHITWOOD & CHITWOOD (1937) and illustrated by further figures in 1950. Its lumen is tri-radiate and its lining sclerotized and greatly thickened locally (see figs. 1 B and 2 C). The thickenings are greatest in the centripetal half of each arm, and are linked with each other by thinner regions. The whole lumen can become circular in cross-section by contraction of the radial muscles to allow the passage of large food particles including whole nematodes. The appearance of this structure in lateral view is shown in figure 2 A, and in dorsal view in figure 2 B. Posterior to the end of the oesophagus there is often a zone of transparent tissue (t.z.), (varying in width in different species) that is usually flanked laterally by three (?) smaller transparent bodies. Behind this is found the sphincter muscle which bears on its posterior face a conical structure (c.o.) of very variable size which projects into the lumen of the intestine. (The sphincter muscle with or without the conical structure is the cardia of some authors. There is no constancy in the use of this term, borrowed from vertebrate anatomy where it refers to the opening of the stomach nearest the heart, and it is meaning- OESOPHAGO-INTESTINAL JUNCTION IN MONONCHIDAE 179
less when applied to a nematode which has neither stomach nor heart). This conical body appears rather "structureless" and is not visible in all specimens. It may be obscured by the dense granules in the intestinal cells, by food in the intestine, or by contraction which brings it up close to the posterior face of the sphincter, or by a combination of these.
THE NON-TUBERCULATE VALVE (Figs. 1 and 3) In Prionchulus muscorum a cross section of the oesophageal lumen appears as shown in figure 1 B from the base of the stoma to a short distance behind the
Fig. 1. Prionchulus muscorum. A. oesophago-intestinal junction; B. transverse section through oeso- phagus; C. transverse section through basal part of oesophagus showing the changed form of the sclerotized lining and the narrowing of the lumen; D. transverse section through the sphincter muscle showing the funnel-shaped valve from behind. c.o. conical organ; f. funnel-shaped valve; g.d. sub-ventral oesophageal gland duct; s.a. supporting annulus; t.r. thickened region of oesophageal lining; t.z. transparant zone.
180 W. C. CLARK
g.d. tr tub. s a f. tub. Co.
Fig. 2. Anatonchus tridentains. A. oesophago-intestinal junction in lateral view; B. oesophago- intestinal juncion in dorsal view; C. transverse section through the oesophageal region; D. section through oesophagus at level 'a' on fig. B. looking posteriorly showing the hollow tubercles uniting centrally; E. transverse section through the sphincter muscle at the level 'b' on fig. B. looking ante- riorly showing the funnel-shaped valve. m.s. muscular ( ?) strand; tub. tubercles; other lettering as for figure 1.
NEMATOLOGICA 5 (1960) PLATE VII
W. C. CLARK: The oesophap-intestinal junction iu Mononchidae.
Fig. 3. Photomicrograph of cesophago-intestinal junction of P. muscorum (alive) showing the funnel shaped valve.
Fig. 4. Photomicrograph of oesophago-intestinal region of /1. tricienialm showing the tubercles and the funnel shaped valve. (Scale applies to both figures). Photos -- C. C. Doncaster.
NEMATOLOGICA 5 (1960) PLATE VIII
W. C. CLARK: The oesophago-intestinal junction in Mononch dac.
a Fig. 5. Photomicrograph of a moulting larva of lotonchus sp, showing the tubercles (arrow) part way up the oesophagus. Both photos --- C. C. Doncaster. OESOPHAGO-INTESTINAL JUNCTION IN MONONCHIDAE 181 duct of the posterior subventral oesophageal gland. Here there is an abrupt change in shape as the thickenings disappear and, in cross section, this basal region now appears as in figure 1 C. The arms of the lumen become shorter, which in lateral view appears to narrow where it passes through the end of the oesophagus and the narrow transparent zone (t.z.) into the sphincter muscle. The lumen narrows here and the greater part of its width is made up of a "supporting annulus" (s.a.) which appears to be attached to the much plicated funnel-like structure (f) that forms the valve proper. The lumen expands greatly as it passes into the sphincter muscle, so becoming funnel-shaped. The exact shape varies somewhat with the state of contraction of the sphincter muscle fibres. There are indications that the "funnel" shares the tripartite nature of the stoma and oesophagus linings (Figure 1 D).
THE TUBERCULATE VALVE
(Figs. 2, 4, 5) In Anatonchus tridentatus transverse sections through the oesophagus appear much the same as in Prionchulus muscorum. Behind the duct of the posterior sub-ventral oesophageal gland there is no marked change in the apparent width of the lumen as it passes into the transparent zone (t.z.). Within the transparent zone, or in the tissue of the sphincter muscle, or partly in both, the peripheral ends of the three arms of the sclerotized lining become inflated, and greatly thickened, forming fairly conspicuous, hollow tubercles or "knobs" (tub). The actual limits of these tubercles in relation to the transparent zone and the sphincter muscle vary somewhat from specimen to specimen. The cavities of the tubercles are con- nected in the centre of the oesophagus (see Fig. 2 D). From this point a narrow duct extends posteriorly, and forms the anterior part (or stem) of the tripartite, plicated funnel-shaped valve. The funnel-shaped valve is similar to that found in the non-tuberculate species, and has a similar supporting annulus which appears to be attached to the posterior part of the tubercles. In A. tridentatus the posterior rim of the funnel is crenulate, but in P. muscoruni the rim tends to be smooth. In moulting specimens of A. tridentatus and two undescribed species of Ioton- chus, the tubercles have been observed part way up the oesophagus in the process of being shed with the rest of the sclerotized lining of the stoma and the oeso- phagus (Fig. 5).
DISTRIBUTION' OF THE VALVE TYPES
The tubercles of the tuberculate type of valve were first reported by DITLEVSEN (1911) in Anatonchus dolichurus (Ditlevsen) and later by STEINER (1914) in Miconchus studeri (Steiner). MICOLETZKY (1922) did not see these structures in A. dolichurus, and regarded those recorded by Steiner as artefacts. Examination of many specimens and species of the Mononchidae has disclosed the following distribution of the two types of valve: 182 W. C. CLARK
(a) non-tuberculate type present in: Mononchus Bastian, 1865 (M. truncatus Bastian, M. papillatus Bastian, M. kastrolli Altherr, and three new species from New Zealand). Prionchulus Cobb, 1916 (P. muscorum (Dujardin) ) Mylonchulus Cobb, 1916 (M. brachyurus (Butschli) and two new species from New Zealand) Cobbonchus Andrassy, 1958 (C. mat/titian/is (Williams) n. comb., and in three new species from New Zealand). (b) tuberculate type valves are present in: Anatonchus Cobb, 1916 (A. tridentatus (de Man), A. dolichurus (Ditlevsen), and in a new species from Rothamsted). lotonchus Cobb, 1916 (I. acutus Cobb, I. brachylaimus Cobb, I. trichurus Cobb, and I. amphigonicus (Thorne), a new species from the Philippine Islands, a new species from the Cameroons, and in six new species, one of which may be syn- onymous with 1. parazschokkei (Allgen) from New Zealand). Miconchus Andrassy, 1958 (M. studeri (Steiner)), and in a new species from Falmouth, Eng- land, though not seen in M. trionchus (Thorne). (These structures are often difficult to detect in specimens which have been mounted on slides for many years). The type of valve found in the genera Brachonchulus Andrassy, 1958, Granon- chulus Andrassy, 1958, Judonchulus Andrassy, 1958, and Sporonchulus Cobb, 1917 is not known as material of these genera was not available.
DISCUSSION The tuberculate type of valve is found in genera in which the tooth or teeth lie in the posterior half of the stoma. Although the teeth in adults of Anatonchus spp. may be situated in the anterior half of the stoma, they are basally situated in the larvae. Further, the structure of the valve alone will serve to distinguish members of the genera Mononchus and lotonchus, which have become inseparable as at present defined. The funnel-shaped valve, which is often a transient feature of fixed material, is not of systematic significance but the tubercles which show up well in fresh and preserved material appear to be useful.
I thank Mr. C. C. Doncaster for taking the photomicrographs, Prof. G. Thorne for reporting on I. acutus, I. amphigonicus, I. trichurus and M. trionchus, and Mr. J. R. Williams for reporting on I. brachylaimus and for the gift of specimens.
ZUSAMMENFASSUNG Die Verbindung von Oesophagus and Darm bei den Mononchiden (Enoplida, Nematoda) Einige morphologische Merkmale der Verbindung von Oesophagus zum Darm verschwinden bei den Mononchiden oft bald nach der Fixierung, besonders die trichterfOrmige Klappe, die von dem Schliessmuskel umgeben ist. Veroffentlichungen iiber diesen Bereich stimmen 'mit der Morphologie der lebenden Nematoden nicht iiberein. Bei den Oesophagus-Darmklappen der Mononchiden unter- scheidet man zwei Typen: 1. den tuberkular-Typ, der durch das Vorhandensein von drei deutlichen OESOPHAGO-INTESTINAL JUNCTION IN MONONCHIDAE 183 hohlen BlUschen am Hinterende der Oesophagus nahe der trichterformigen Klappe charakterisiert ist und 2. den nicht-tuberkular-Typ, bei dem die Blaschen fehlen und die OesophagusfUhrung nahe dem hinteren Ende enger wird. Der tubercular-Typ wurde bei Anatonchus, lotonchus und Miconchus gefunden, der nicht-tuberkular-Typ trat bei Mononchus, Prionchulus, Mylonchulus und Cobbonchus auf. Mononchus mauritianus Williams 1958 wurde in die Gattung Cobbouchus Andnissy tiberftihrt.
LITERATURE
ANDRASSY, I. (1958). Uber das System der Mononchiden (Mononchidae Chitwood, 1937; Nema- toda); Ann. hist.-nat. Mus. hung. n.s. 9, 50, 151-171. CHITWOOD, B. G. & CHITwooD, M. B. (1937). The histology of nemic oesophagi VIII. The oeso- phagus of representatives of the Enoplida, J. Wash. Acad. Sci., 27, 517-531. -- (1950). An introduction to Nematology. Section 1, Anatomy; revised edition, Baltimore, Chitwood. DITLEVSEN, H. (1911). Danish Free-living Nematodes, Vidensk, Medd. dansk naturrh. Foren. Kbh. 63, 213-256. MICOLETZKY, H. (1922). Die freilebenden Erd-Nematoden, Arch. Naturgesch. 87, Abt. A. (8 & 9) 1-650. STEINER, G. (1914). Freilebende Nematoden aus der Schweiz, Arch. Flydrobiol. (Plankt.) 9, 259-276.
Received for publication: July 1, 1960 Nematologica 5 (1960): 184-198. E. J. Brill, Leiden
4. REDESCRIPTION OF MONONCHUS TRUNCATUS BASTIAN, M. PAPILLATUS BASTIAN AND PRIONCHULUS MUSCORUM (DUJARDIN) (ENOPLIDA, NEMATODA)
BY
W. C. CLARK
Rothamsted Experimental Station, Harpenden, Herts., England 1)
1) At present on study leave from Entomology Division, D.S.I.R., Nelson, New Zealand. Three species of the Mononchidae are redescribed; Mononchus truncatus Bas- tian because it is the type species of Mononchus, and M. papillatus Bastian and Prionchulus muscorum (Dujardin) because of the confusion between them (ALT- HERR, 1938). Both genera are redefined. The nematodes examined were collected in England; M. truncatus, Falmouth (type locality) and Chippenham Fen; M. papillatus, Broadmoor Institution, Berks (type locality), Falmouth, and Woburn, Beds.; P. muscorum, Broadmoor Institu- tion, Berks, Falmouth, Woburn, Beds., and Rothamsted. Moss from the Jardin des Plantes, Paris (type locality and habitat of P. muscorum) yielded no specimens. Measurements are of eelworms killed by heat, fixed in F.A. 4 : 10 and transferred to glycerine by Baker's method (GooDEv, 1957). The nematodes were examined alive or narcotized because details of the papillae and of the oesophago-intestinal junction become obscured after fixation (CLARK, 1960).
MONONCHIDAE Chitwood and Chitwood 1937 Emend. Tripyloidea. Cuticle smooth or nearly so; lateral fields absent. Head broad, sub-rounded or truncated; not, or only slightly offset; with six lips and two rings of papillae, the inner ring with six or eighteen, the outer ring with six, ten, or fourteen papillae. Amphids level with the anterior half of the stoma, moderate to small size, pouch-like, with crescentic transverse apertures. Stomal large and wide, heavily sclerotized, tripartite and always armed with single immovable, dorsal tooth; subventral teeth present or absent, smaller or equal to the dorsal tooth. Teeth directed anteriorly or posteriorly. Subventral denticles absent or present in transverse or longitudinal rows, or scattered. Oesophagus very muscular, anteriorly enveloping the posterior end of the stoma, widening slightly posterior- ly, always non-bulbar. Nerve ring encircles the oesophagus at one quarter to one third of its length. Dorsal oesophageal gland opens into oesophageal lumen behind nerve ring; one pair of subventral glands open near the posterior end of oeso- phagus, and the other pair between the other two ducts. Oesophageal lumen tri- REDESCRIPTION OF THREE SPECIES OF MONONCHIDAE 185
quetrous, lining sclerotized. Oesophago-intestinal junction with sphincter muscle and lightly sclerotized valve apparatus (usually not visible in fixed specimens). Intestine a simple tube, cells usually with granular contents. Pre-rectum in males only; rectum short, usually straight. Tail long or short, variously shaped, sexes similar or dissimilar; usually with three caudal glands which may or may not discharge through a terminal or subterminal orifice ( = "spinneret" of Cobb). Tail usually with paired lateral cuticular pores. Females Genital organs mostly paired, opposed, but may be single, either pre- or post-vulvar; ovaries short, reflexed. Only a few eggs in the uteri at a time. Males Testes paired, opposed, out- stretched. Spicules simple, paired and free. Gubernaculum present; often asso- ciated with complex lateral accessory pieces. Supplements in a single ventro-median series, sometimes echinulate, roughly equidistant. In some species males are rare or unknown. Found in soil, moss, liverworts, forest litter, and freshwater. Some show a distinct preference for wet soils. Type genus: Mononchus Bastian, 1865.
Mononchus Bastian, 1865 Mononchidae. Stoma large, almost parallel sided, usually with pointed base; armed with a single, stout, anteriorly directed, dorsal tooth, its apex lying in the anterior half. A low, untoothed, ventral ridge may be present. Oesophago-intes- tinal junction of the non-tuberculate type (CLARK, 1960); i.e. with a stout sphinc- ter muscle surrounding a lightly sclerotized, funnel-shaped extension of the oesophageal lining; never with sclerotized knobs or tubercles. Ovaries paired, rarely single (M. monohystera Cobb). Spicules simple, separate, arcuate. Guber- naculum simple, or enveloping the spicules laterally, or associated with complex accessory pieces. Tails mostly short, conoid; or long, conoid at first with a cylin- drical end part. Found in freshwater, soil, leaf mould, mosses, and liverworts. Type species: Mononchus truncatus Bastian, 1865.
Mononchus truncatus Bastian, 1865 Figures 1 A-I Mononchus truncatus Bastian, 1865; p. 101, pI. IX, figs. 25, 26. Mononchus macrostoma Bastian, 1865; p. 101-102, pl. IX, figs. 29, 30. .Mononchus longicaudatus Cobb1,1839;3p;.p 13.112 . fig. 2. Mononchus macrostoma Cobb, 1893; Mononchus (Mononchus) truncatus Cobb, 1916; p. 195. Mononchus (Mononchus) macrostoma Cobb, 1916; p. 195. Mononchus (Mononchus) longicaudatus Cobb, 1916: p. 195. Mononchus macrostoma var. filicaudatus Schneider, 1937; p. 48, figs. 5a, b. nec. Mononchus macrostoma var. armatus Daday, 1897; p. 108, fig. 14. (= M. dadayi Micoletzky, 1914 sp. inquirenda). nec. Afononchus longicaudatus Schuurmans Stekhoven & Teunissen 1938; p. 85, figs. 44a, b, not of de Man nor of Cobb. nec. Mononchus macrostoma Schuurmans Stekhoven & Teunissen 1938; p. 86, figs. 45a, b. 186 W. C. CLARK
B.
F
A.
D
E.
Figure 1. Mononchus truncatus. A. Head region; B. en face view of head; C. cross section of stoma at the level of the dorsal tooth; D. oesophago-intestinal junction; E. lateral view of the vulva; F. ventral view of vulva; G. sectional view of vagina; H. female tail; I. abnormal female tail. REDESCRIPTION OF THREE SPECIES OF MONONCHIDAE 187
Falmouth
Neotype ? L = 1.92 mm; a = 28; b = 3.9; c = 8; V = 14 55.5 13 (n = 9) L = 1.86 mm; (s = ± 0.143 mm) (range 1.65-2.14 mm) a = 26-40; b = 3.4-4.3; c = 6.4-8.6; V = 10-22 48.4-55.5 10-15
Chippenham Fen (n = 2) L = 1.67-1.85 mm; a = 33-36; b = 3.6-3.8; c = 5.8-6.4; v = 9-11 53.4-54.3 7-12 Neotype ? from moss at the edge of Swan Pool, Falmouth, England. Slide no. 143/2/4 Nematology Dept., Rothamsted Experimental Station, Har- penden. Cuticle smooth 2 p, thick, subcuticle 2 p, thick. No lateral fields. Head sub- rounded, not offset, lips rather small. Amphid apertures small transverse slits at the level of the dorsal tooth apex. In en face view the lip region as in figure 1B. Lips six, rounded on the inner edge, with two rings of papillae; inner ring of eighteen (three on each lip arranged in a short arc) and outer ring of ten (one at the peripheral apex of each lip, and one placed sub-laterally on each of the sub-median lips). In this view amphid apertures appear as crescentic slits. At level of dorsal tooth apex stoma deeper than wide, and the sclerotized elements are thickened where they abut. In lateral view stoma almost three times as long as broad. Tooth apex at about • 20-28 % of the stoma length. Anterior edge of the tooth straight, and sloping slightly posteriorly from apex. Posterior margin of tooth gently arcuate and mer- ging imperceptibly with the stoma wall. Stoma wall with faint transverse striae, dorsal wall slightly indented below tooth apex. Stoma walls inarched above the tooth apex. Posterior elements not clearly marked off from anterior ones. Oesophagus slightly expanded and surrounding basal third of stoma, then nar- rowing a little to the nerve ring at one quarter of the oesophageal length, then expanding again to occupy five-ninths of the body width. Dorsal oesophageal gland duct occurs at half the oesophageal length, duct of one pair of subventral oesophageal glands occurs at three-quarters of the oesophagus length, and the other duct at one oesophagus width from the end. Oesophago-intestinal junction with a narrow transparent zone interpolated between base of oesophagus and sphincter muscle, and flanked laterally by three (?) transparent bodies. Sphincter muscle solid, rather disc-like with an obtusely rounded conical structure projecting into intestinal lumen from the posterior face of the sphincter. Sclerotized lining of the oesophagus constricted near base of oesophagus and becomes less heavily sclerotized. After passing through the transparent zone and into the sphincter muscle the sclerotized lining fans out and becomes funnel-shaped. The walls of the "funnel" bear a number of plications. (The actual shape of this structure varies with the state of contraction of the muscle fibres). The lightly sclerotized "fun- nel" and the sphincter muscle form a valve between the oesophagus and the in- 188 W. C. CLARK testine (Figure 1D). Intestine a simple tube with abundant intra-cellular granules. In the female it passes to the right of the anterior and to the left of the posterior ovary. No pre-rectum in the female. Rectum straight, length equal to anal body width. Vulva a transverse slit, one sixth body-width; lips oval, very feeble. Vagina feebly muscular, extending across less than one third of body-width; its lumen cruciform. Genital organs paired, opposed, ovaries reflexed through half the length of the uterus and oviduct. Up to four ova in the uteri at a time. Tail conoid at first, then tapering more gradually to become almost cylindrical in the posterior two-thirds; tip rounded and slightly swollen. Three large caudal glands present, duct terminal. Paired lateral cuticular pores usually as shown in figure 1H. Male (from DE MAN, 1884) "Schwanz des Mannchens von gleicher Gestalt wie des Weibchens. Spicula sehr schlank, diinn, in eine sehr stumpfe Ecke ge- bogen, mit zentralem Verdickungsstreife, von zwei ebenso schlanken, aber viel kiirzeren akzessorischen Stiicken begleitet. Cuticula beim MHnnchen vor After schrag gestreift; 20 Papillen, nahe beieinander gelegen und kaum hervorragend, vor dem After und drei mediane ventrale wie auch einige laterale Papillen auf dem eigenlichen Schwanze." L = 1.9 mm.
REMARKS M. truncatus and M. macrostoma are probably the same species. Apart from the supposed absence of cephalic papillae in M. truncatus, which is either an artifact or an oversight, the other differences mentioned by Bastian are unimpor- tant. ANDRASSY (1958) has drawn attention to the variability of this species, with which he synonymised poorly known species such as M. dadayi Micoletzky, 1914, and M. obtusus Cobb, 1917. The six small tooth-like, cuticular, circum-oral spines mentioned by Coss (1917) in M. dadayi are the crudely drawn papillae. Daday's figures and descriptions are inadequate for identification. Butschli's figures of M. obtusus (copied by Cobb) are based on a partially distorted head which has been badly drawn. The stoma shown in these figures is of a different shape from that of M. truncatus and with the tooth apex at 39 per cent of the stoma length. The tail has a different shape, and the papillae are quite different. The status of Cobb's M. ion gicaudatus and M. me galaimus is not easily decided. M. longicau- datus is very similar to M. truncatus. These two species differ mainly in that males of the former have sixteen supplements compared with twenty in the latter, but as the range of variation of this character is not known, this criterion is of doubt- ful value for their separation. When Cobb erected M. longicaudatus in 1893 he does not appear to have seen M. truncatus (or M. macrostoma) from Europe. M. longicaudatus and Al. truncatus are best regarded as synonyms until they can be compared. M. megalaimus is strikingly different from M. truncatus and M. longicaudatus in the feeble development of the lips and the close approximation of the anterior end of the stoma to the lips. Cobb's figure is not strictly lateral REDESCRIPTION OF THREE SPECIES OF MONONCHIDAE 189 so comparison of the teeth and stoma shape is not possible. M. megalaimus stands until the American mononchs are revised and its status determined. I regard M. dadayi Micol. and M. obtusus Cobb as species inquirendae.
A.
D F A B O C E 6(
E.
Figure 2. Mononchus papillatus. A. Head region; B. en face view , of head (stoma cross section at the level of the dorsal tooth apex); B'. Enlarged view of ventral part of stoma showing ventral ridge in section; C. oesophago-intestinal junction; D. posterior half of female genital organs; E. ventral view of the vulva; F. female tail.
Mononchus papillatus Bastian Figures 2A-F Mononchus papillatus Bastian, 1865; p. 101, pl. IX, figs. 27, 28. Mononchus (Mononchus) papillatus Cobb, 1916; p. 195. 190 W. C. CLARK lotonchus papillatus Altherr, 1950; p. 4. Prionchulus papillatus Altherr, 1952; p. 9. Mononchus papillatus Andrassy, 1958; p. 1865. nec Mononchus papillatus etc. in Butschli; 1873; Ditlevsen, 1911; Brakenhoff, 1914; Menzel, 1914; Hoffmanner & Menzel, 1915; Micoletzky, 1922 (partim); Micoletzky, 1925; AlIgen, 1929; Alt- herr, 1938; de Coninck, 1939; Schuurmans Stekhoven & Teunissen, 1938; Schuurmans Stekhoven & Mawson, 1954. nec Mononchus bastiani de Man, 1876.
Broadmoor. Neotype y L = 1.29 mm; a= 29; b = 3.9; c = 19; V = 16 62.2 13 (n = 9) L = 1.23 mm; (s = ± 0.292 mm) (range 1.01-1.30 mm); a = 22-29; b = 3.6-3.9; c = 14-19; V = 8-16 60-67.7 9-14 Neotype from turf, Broadmoor Institution, Berks. England. (Type locality). Slide no. 143/1/7 Nematology Dept., Rothamsted Experimental Station, Har- penden, England. Males extremely rare; only description THORNE (1924). Cuticle smooth 1.7 11 thick; subcuticle smooth 1.7 p, thick. No lateral fields. Lip region scarcely offset, cephalic lips and papillae conspicuous in fresh material, less so in preserved specimens. Lips six, equal, symmetrical, inner margin rounded, outer margin obtusely angular. In en face view the papillae are readily seen in two rings, the inner ring of eighteen (three on each lip arranged in an almost straight line across the lip,) and an outer ring of fourteen (one at the apex of each lip and a sub-lateral pair on each of the sub-median lips). The innervations of the three inner papillae are distinguishable in lateral view, but usually only one papilla in the outer ring on the sub-median lips is visible in this view. Amphid apertures appear as crescentic slits in en face view. Stoma squarish in cross section at level of dorsal tooth apex. In this view dorsal tooth appears triangular in cross section, spreading slightly onto the dorsal wall. Opposite the dorsal tooth apex the abut- ting edges of the anterior subventral components of the stoma are thickened on the inner face. (This thickening forms the ventral ridge seen in lateral view). In lateral view the amphid apertures are difficult to see, but are situated at the level of the dorsal tooth apex. Viewed laterally the sclerotized stoma is cup-shaped, half as wide as long, and half as wide as the head width. Dorsal tooth apex occurs at 15-21 % of the stoma length. Anterior margin of tooth straight, hori- zontal or nearly so; posterior edge merges smoothly into stoma wall without any re-entrant angle. Dorsal wall of stoma indented a little posterior to tooth apex. On the ventral wall the tickened, abutting edges of the antero-ventral elements of the stoma form a low, untoothed ridge extending from a point opposite the dorsal tooth apex to the posterior limit of the anterior elements. Anterior to the tooth apex and ventral ridge, the stoma walls arch inwardly and restrict the size of the anterior aperture to about a third of the greatest width of stoma. Suture between anterior and posterior elements obscure. Postero-dorsal element much thickened anteriorly, but thins rapidly towards oesophageal lumen. Anterior three- REDESCRIPTION OF THREE SPECIES OF MONONCHIDAE 191
quarters of stoma surrounded by thin connective tissue sheath; posterior quarter embedded in anterior part of oesophagus. Oesophagus muscular and glandular, narrowing slightly from stoma base to nerve ring at a quarter of oesophageal length, then expanding with general body contour to occupy slightly more than half the body width. Dorsal oesophageal gland duct opens into oesophageal lumen at mid point; one sub-ventral gland duct opens at two-thirds of its length; remaining duct opens half an oesophagus-width from end. Oesophago-intestinal junction more complex than existing figures indicate. Base of the oesophagus sub-rounded; from its posterior face an annulus of transparent tissue is surrounded by the sphincter muscle. Sclerotized lining of oesophagus becomes much thinner near base of the oesophagus; constricted where it passes through posterior end and starts to expand again as it passes through the transparent annulus, becoming funnel-shaped within the sphincter muscle. At- tached to the posterior face of sphincter is a small conical projection, the shape and size of which varies from specimen to specimen. On either side of the oeso- phagus base and anterior to the sphincter muscle are small discrete transparent bodies. In life the thin sclerotized funnel is constricted by the sphincter muscle, and the whole forms a valve. Food passes rapidly through this valve. Intestine a simple tube with abundant dark granules in its cells, passing to the right of the anterior and to the left of the posterior ovary. No pre-rectum in the female; rectum straight, length almost equal to the anal body-width. Vulva a transverse slit one fifth body-width, with slightly thickened oval lips. Vagina muscular, extending across one third of body-width, and uniting with paired uteri. Genital organs paired, opposed, ovary reflexed through half to two-thirds the length of oviduct and uterus. Ovary half as wide as body, oocytes in a single row. No sphincter muscle or glandular region observed at the oviduct- uterus junction. Usually only one mature egg in the uteri; occasionally one in each uterus. Tail conoid, ventrally arcuate, short. Three caudal glands present but no ter- minal duct; two pairs of lateral cuticular pores seen. Differential diagnosis Mononchus papillatus Bastian is most frequently confused with Prionchulus muscorum (Dujardin). For differentiation of these two species see page 192.
REMARKS Several species may be hidden under the name M. papillatus. It is almost certain that the larva assigned to this species by SCHUURMANS STEKHOVEN & MAWSON (1954) from Soltanbad, Iran (L = 2.5 mm) does not belong here. The Al. papil- latus recorded from New Zealand and the Campbell Islands by ALLGEN (1929) are probably P. muscorum (Dujardin), though rather small (L = 1.45 mm). The smallest specimen of this species I have from New Zealand is 1.68 mm long. The size of Mononchids varies considerably from habitat to habitat and 1.45 mm may be written within the range of variation for Campbell Island populations. It 192 W. C. CLARK is uncertain whether Allgen's dimensions relate to a specimen from New Zealand or Campbell Island. M. bastiani de Man, 1876 has often been synonymised with M. papillatus but according to P. A. A. LooF (in litt.) de Man's specimen possesses the denticulate ridges of P. muscorum and is a synonym of that species. M. cristatus Bastian, 1865 was synonymised with M. papillatus by ANDRASSY (1958). Bastian's description is brief and the figure (only specimen) has an obvious post-mortem artefact on the tail. The dimensions given are for an "imma- ture female" for which L = 1.1 mm but FRANKLIN ( 1955 ) has shown that for Aphelenchus spp. Bastians' measurements are 25 per cent too large. This holds for at least some of his mononchs. The corrected length of M. cristatus is 0.82 mm which is very small for papillatus; the value (c = 6) for cristatus indicates a tail two to three times as long as that found in papillatus. M. cristatus has not been recorded since it was described, and could not be recognised from the data avail- able. I therefore regard it as a species inquirenda. Over the years the names Mononchus papillatus and Prionchulus muscorum have been used about equally for species with denticulate and non-denticulate ridges. The confusion is well known. Dujardin stated that denticulate ridges were present in muscorum, but Bastian stated of papillatus "tooth single," and did not figure any ridge on the ventral stoma wall. Dujardin gave the length of muscorum as 2.56 mm, and Bastian's papillatus was 1/iith in. (= 2.31 mm). Bastian's meas- urements are often 25 per cent too large (see above); this appears to hold for M. macrostoma and also appears likely for M. papillatus. If applicable, this reduces the length to 1.73 mm which is one fourth larger than any of my specimens from Broadmoor. This difference is not great for mononchids some of which (e.g. lotonchus parazschokkei (Allgen), M. propapillatus, Cobbonchus pounamua n. spp. CLARK in press) vary by a factor greater than two. No definite conclusions can be drawn from measurements, nor from Bastian's figure of the head which is distorted. One can only speculate whether Bastian overlooked a denticulate or a non-denticulate ridge. We may note that he knew of Dujardin's species as he reproduced the description. In the absence of any type specimens it is impossible to prove synonymity, or that two distinct species are indicated. Because both names have long standing I prefer to restrict them as Coss, 1917 and T. GOODEY, 1942, 1951 have done, using M. papillatus for the species with a non-denticulate ridge, and P. muscorum for the species with two denticulate ventral ridges.
Prionchulus Cobb, 1916 Mononchidae. Stoma large, almost parallel sided, armed with a single, stout, anteriorly directed, dorsal tooth situated in the anterior half, and with two sub- ventral, denticulated, longitudinal, sclerotized ridges (only one visible in lateral view). Number of denticles variable, usually fewer and less well developed in larvae. Where the denticles are few they tend to be aggregated at the anterior
REDESCRIPTION OF THREE SPECIES OF MONONCHIDAE 193
Figure 3. Prionchulus muscorum. A. Head region; B. en face view of head; cross section of stoma at the level of the dorsal tooth apex; C. lateral views of the denticulated ridges of some larvae showing variation in denticulation; D. ventral denticulated ridges viewed from the dorsal side; E. oesophago-intestinal junction; F. ventral view of the vulva; G. lateral view of female genital organs; H. female tail. 194 W. C. CLARK end of the ridges. Oesophago-intestinal valve non-tuberculate (CLARK, 1960); i.e. with stout sphincter muscle partially lined with lightly sclerotized, funnel-shaped extension of the oesophageal lining; never with sclerotized knobs or tubercles. Female genital organs paired, opposed, ovaries reflexed. Vulva 47-67 70. Spicules stout, arcuate; gubernaculum simple, but in all known males is associated with bifid lateral pieces. Tail usually short and conoid, rarely long and slender. Caudal glands present, no terminal duct. Paired lateral cuticular pores on tail (in males of P. longus Thorne these pores may be situated on papillae). Males rare or common. Found in soil, moss, leaf mould, and in sulphur springs (P. thiocreno- bius Pax and SoOs).
Type species: Oncholaimus muscorum Dujardin, 1845 Prionchulus muscorum (Dujardin, 1845) Chitw. & Chitw., 1937 Figures 3A-H
Oncholaimus muscorum Dujardin, 1845; p. 237. Mononchus muscorum Bastian, 1865; p. 103. Mnnonchus bastiani de Man, 1876; p. 184, pl. XIII, fig. 49a, b. Mononchus (Prionchulus) muscorum Cobb, 1916; p. 195. Mononchus (Prionchulus) muscorum macrolaimus Cobb, 1917; p. 163, fig. 38. Prionchulus muscorum Chitwood and Chitwood 1937; p. 517. Mononchus papillatus in Biitschli, 1873; Ditlevsen, 1911; Menzel, 1914; Hoffmanner & Menzel, 1915; Micoletzky, 1922 (partim); Micoletzky, 1925; Schneider, 1929 (partim); AlIgen. 1929: de Coninck, 1939.
Broadmoor ?? (n = 21) L = 2.12 mm; (s = ± 0.120 mm) (range = 1.91-2.32 mm) a = 26-33; b = 3.3-4.4; c = 13-17; V = 7-9 61.3-66.7 7-22
Cuticle smooth, 2.5 p. thick, subcuticle 1.5 p. thick. No lateral fields. Lip region not markedly offset. Lips and cephalic papillae readily distinguishable in lateral view (papillae less prominent in fixed material). Lip region hexagonal in en face view; lips six, equal, rounded on inner edge, obtusely angled on peripheral edge. Cephalic papillae in two rings, inner one of eighteen (three on each lip arranged in form of an inwardly directed obtuse triangle) and outer ring of fourteen (one placed at the apex of each lip, and a pair placed slightly laterally to this on each of the sub-median lips). Amphid apertures crescentic slits below the level of the lips. In this view the tripartite nature of the stoma is clearly seen. At the level of the dorsal tooth apex stoma rather triangular in cross section. Along the ventral suture the ventro-lateral elements are slightly invaginated and thickened on the inner surface where they abut. Transverse thickenings along these ridges form the denticulations characteristic of the genus. Dorsal tooth triangular in cross section spreading considerably onto the dorsal wall of the stoma. In lateral view the inner ring of papillae is easily distinguished, but, of the outer ring, only the apical papillae are easily seen. In lateral view pouch-like amphids REDESCRIPTION OF THREE SPECIES OF MONONCHIDAE 195 are situated between the tooth apex and the anterior limit of the sclerotized stoma. Stoma twice as long as broad, cup-shaped with pointed base. Dorsal tooth strong, with apex at 25-30 % of stoma length. Anterior edge of the tooth straight, almost horizontal or sloping slightly posteriorly from the apex. Posterior or buttress edge merging imperceptibly with the dorsal stoma wall. On the ventral wall of the stoma lie the denticulate ridges bearing nine to fourteen denticles in the mature female. In larvae these denticles are irregular in development and number. Dorsal wall of stoma indented laterally to the tooth; both walls inarched above the tooth apex, and the anterior orifice of the stoma restricted to two-fifths of the greatest diameter of the stoma. Suture between the anterior and posterior stomal elements obscure. In lateral view the dorsal posterior element appears much thicker than the ventral ones, but becomes thinner towards the oesophageal lumen. Basal quar- ter of the stoma enveloped by the anterior end of the oesophagus. Oesophagus uniform in width to the nerve ring which occurs at a quarter of its length; then expanding a little with the general body contour and occupying three-fifths of the body width. Dorsal oesophageal gland duct opens into the oesophageal lumen at 60 per cent of the oesophagus length and the subventral gland ducts open at 80 and 95 per cent respectively. Oesophago-intestinal junction with thin transparent zone interpolated between sphincter muscle and base of oesophagus. Flanked on either side by 3 (?) smaller transparent bodies. Sphincter stout and disc-like. A little before the end of the oesophagus its sclerotized lining becomes much thinner and is constricted as it passes through the oesophagus base and the transparent area. In the sphincter, this flares out again to form a shallow bell-like structure, much plicated in its mid- region. Its tripartite nature detectable only with difficulty. The shape of the sclerotized structure varies with the contraction of the sphincter muscle fibres. Posterior surface of sphincter bears a short conical structure the shape of which is rather variable, invisible in most specimens. Intestine a simple tube, cells with abundant dark granules. Intestine passes to the left of the anterior and to the right of the posterior ovary. No pre-rectum; rectum straight, equal to anal body- width. Vulva a transverse slit, one-third as wide as the body, with broad, variable, slightly thickened lips. Vagina moderately muscular, extending inwards about a third of body width, and uniting with the uteri. Genital organs paired, opposed, ovaries reflexed through a third to half the length of oviducts and uteri. Oocytes arranged in a single row. No sphincter or glandular region between the oviducts and uteri. Length of the uteri varies with the number of mature eggs contained. Egg shells may be ridged. Often only one mature egg in each uterus, but there may be two in each. Tail short, conoid, ventrally arcuate. Caudal glands present, but no spinneret. Two pairs of lateral cuticular pores as shown in figure 2F. Male (after SCHNEIDER, 1923) n = 2 L = 2.16-2.24 mm; a = 36-37; b = 4.0-4.14; c = 18-18.7. 196 W. C. CLARK
Supplements sixteen evenly spaced, the first, three tail lengths from the anus. Spicules paired, large, arcuate. Gubernaculum small, partially enfolding the spi- cules. Notched lateral accessory pieces present. Tail similar to female.
REMARKS One adult female P. muscorum from Broadmoor appeared to be undergoing an adult moult. The specimen had the normal, fully developed genital structures, a patent vulva in the cuticle that was being shed, and another lying beneath it in the newly formed cuticle. The stoma had two sclerotized linings; one in the pro- cess of being moulted. There were no mature eggs in the uteri, the oocytes in the ovaries were rather small, and the length of the eelworm was only 1.62 mm (smal- ler than any other females I have measured) and therefore probably precociously mature, rather than undergoing an additional moult. P. muscorum appears to be a cosmopolitan species. Because the figures of Mononchus muscorum of SCHUURMANS STEKHOVEN & TEUNISSEN (1938) lie quite outside the range of variability encountered so far this species, the spec- imens from which these figures were drawn are believed to be a new and un- described species. No measurements were given, and the males were not described or figured. ANDRASSY (1958) provides a synonymy for P. muscorum but gives no reasons for including some of the forms. M. papillatus forma macrodon Fuchs is based on a specimen of papillatus with a partially collapsed stoma. There are no grounds for placing it in this genus as denticulate subventral ridges are neither figured nor mentioned. He has overlooked the echinulate eggs of P. punctatus Cobb, a feature unknown in muscorum. The status of M. (P.) longicollis Cobb is in doubt and as it appears to be based on a single larva I regard it as a species inquirenda. M. (P.) muscorum macrolaimus Cobb is of doubtful status; there appear to be some differences between the two forms but until specimens can be compared I agree with Andrassy and regard it as a synonym of P. muscorum. The single male of P. spectabilis (Ditlevsen) described by MEYL (1955) does not agree with the characters of spectabilis; there are far too many denticles on the ventral ridges and the length is only 1.52 mm whereas Ditlevsen's males measured 3.6 mm. Meyl's specimen may be a male of P. muscorum, but until similar specimens are found associated with females it is best to regard P. spectabilis Meyl, 1955 nec Ditlevsen, 1911 as a species inquirenda.
CONCLUSION Adults of M. papillatus and P. muscorum are readily distinguishable. Most of the confusion between them has arisen from attempted determinations of larvae, and probably from the intrusion of a third species, P. punctatus Cobb, 1917 ( = M. muscorum of BRAKENHOFF, 1914), a species characterised by poorly developed, rather short denticulate ridges in the stoma, and by the presence of echinulate eggs. Echinulate eggs are not found in muscorum, but have been re-
REDESCRIPTION OF THREE SPECIES OF MONONCHIDAE 197
corded by BRAKENHOFF (1914), and ALTHERR (1938). The figures of these authors are not of typical muscorum or papillatus. M. echinulatus Altherr, 1938 appears to be a lapsus for M. punctatus. Specimens of P. punctatus were not available for consideration. The described species of Prionchulus are chiefly to be recognised from the char- acters set in Table I. Most species are imperfectly known, the range of variation being quite unknown, and probably many more species await description.
TABLE I Characters of the described species of Prionchulus no. of species L. c tail 6 L. c denticle on ridges muscorum (Dujardin) .1.9-3 mm 12.5-17 conoid 9-14 short
longus (Thorne) 2.14 mm 20 conoid 2.0 mm 27 20 short punctatus Cobb 1.7 mm .14.3 conoid 12 (echinulate eggs) short (ridges short) spectabilis (Ditl.) 4.0 mm 8 conoid 3.6 mm ? 7 short thiocrenobius 1.6 mm 5.5 longish — 16-17 (?) Pax & Soos slender (V = 47 %) (ridges short) tip swollen
M. papillatus and P. muscorum may be readily separated as follows: M. papillatus P. muscorum Ventral ridge low, never denticulate Ventral ridges prominent, always denticulate; denticulations variable in larvae. Inner papillae on each lip arranged in a straight Inner papillae on each lip arranged in an obtuse line triangle. Stoma squarish in cross section at the level of Stoma rather triangular in cross section at level dorsal tooth apex of dorsal tooth apex. Ventral ridge terminates at level of tooth apex Ventral ridges extend a little anterior to dorsal tooth apex. Not more than two eggs in uteri at a time Up to four eggs in uteri at a time. L = 1.0-1.36 mm (British specimens) L = 1.91-2.64 mm (British specimens). A soil dwelling species Predominantly a moss species.
ZUSAMMENFASSUNG
Neubeschreibung von Mononchus truncatus Bastian, M. papillatus Bastian und Prionchulus muscorum (Dujardin) (Enoplida, Nematoda) Mononchus truncatus Bastian ( = M. macrostoma Bastian) und M. papillatus Bastian werden aus topotypischem Material neubeschrieben und Enotypen bestimmt. Prionchulus muscorum (Dujar- din 1845) Cobb 1916 wurde aus britischen Populationen neubeschrieben. Die Unterschiede von Al. papa/cans und P. muscorum sind folgende: 198 CLARK, REDESCRIPTION OF THREE SPECIES OF MONONCHIDAE
Al. papillatus P. muscorum Ventrale Leiste niedrig, nie gezahnt. Ventrale Leisten hervorstehend, stets gezahnt, Zahnelung unterschiedlich bei Larven. Innere Papillen an jeder Lippe in einer geraden Innere Papillen an jeder Lippe zu einem stump- Linie angeordnet. fen Dreieck angeordnet. Mund im Querschnitt fast quadratisch in Hohe Mund im Querschnitt mehr dreieckig im Hobe der dorsalen Zahnspitze. der dorsalen Zahnspitze. Ventrale Leiste endet out der Hohe der dor- Ventrale Leisten erstrecken sich ein wenig nach salen Zahnspitze. vorn zur dorsalen Zahnspitze. Im Uterus nicht mehr als 2 Eier gleichzeitig. Im Uterus bis zu 4 Eier gleichzeitig. L = 1,0-1,36 mm (Britische Proben). L = 1,91-2,64 mm (Britische Proben). Bodenbewohnende Art. Vorwiegend eine moosbewohnende Art.
P. punctatus Cobb 1917 kann die Bestimmung beider Arten erschweren. Al. dadayi Micoletzky 1914, Al. obtusus Cobb 1917, Al. cristatus Bastian 1865 and P. longicollis Cobb 1917 werden als species ikiquirendae angesehen. Alononchus echinatus Altherr 1938 ist ein Lapsus fur P. punctatus Cobb.
REFERENCES ALLaN, C. (1929). "Ober einige freilebende Moosnematoden, Nyt Mag. Naturv. 67, 211-230. ALTHERR, E. (1938). Le faune des mines des Bex, avec etude speciale des Nematodes, Rev. suisse Zool., 45, 567-720. ANDRASSY, I. (1958). Uber das System der Mononchiden (Mononchidae Chitwood, 1937; Nema- toda), Ann. Hist.-nat. Mus. hung. n.s. 9, 50, 151-171. BASTIAN, H. C. (1865). Monograph on the Anguillulidae Trans. Linn. Soc. Loud. 25, 73-84. BRAKENHOFF, H. (1914). Beitrage zur Kenntnis der Nematodenfauna des nordwestdeutschen Flach- landes, Abhandl. Naturw. V erein, Bremen; 22, 267-311. CLARK, W. C. (1960). The oesophago-intestinal junction in the Mononchidae (Enoplida, Nema- toda), Nematologica, 5, 178-183. Cons, N. A. (1917). The Mononchs (Mononchus Bastian, 1865), a genus of freeliving predatory nematodes. Soil Sci., 1, 431-486. DITLEVSEN, H. (1911). Danish free-living nematodes, V iclensk. .Medd. dansk naturrh. Force. Kbh., 63, 213-256. FRANKLIN, M. T. (1955). A redescription of Aphelenchoides parietinus (Bastian, 1865) Steiner, 1932. J. Helm., 29, 65-76. GOODEY, J. B. (1957). Laboratory methods for work with plant and soil nematodes. Tech. Bull. 2 Min. Ag. Fish. Food, London, H.M.S.O. 47 pp. GOODEY, T. (1942). Observations on Mononchus tridentatus, M. brachyuris and other species of the genus Mononchus, J. Helm. 20, 9-24. (1951). Soil and Freshwater Nematodes, London, Methuen, 390 pp. MEYL, A. (1955). Uber einige an den deutschen Kiisten vorkommende Arten des Nematodengattung Mononchus Bastian 1865, Kieler Meeresforsch., 11, 80-85. SCHNEIDER, W. (1923). Niederrheinische freilebende Nematoden, Zool. Anz., 56, 264-281. SCHUURMANS STEKHOVEN, J. H. & MAWSON, P. M. (1954). Freeliving Nematodes, mostly from Asia, Ark, Zool. 7, 273-279. — & TEUNISSEN, R. J. H. (1938). Nematodes libres terrestres, Expl. du Parc National Albert Mission G. F. de Witte 1933-1935, 22, 1-229. THORNE, G. (1924). Utah nemas of the genus Mononchus. Trans. Amer. micr. Soc., 43, 157-171.
Received for publication: July 1, 1960 Nematologica 5 (1960): 199-214. E. J. Brill, Leiden
5a. NEW ZFALAND MONONCHIDAE (ENOPLIDA, NEMATODA) I THE GENERA MONONCHUS BASTIAN AND PRIONCHULUS COBB
BY
W. C. CLARK Rothamsted Experimental Station, Harpenden, Herts, England 1)
Free-living nematodes of the New Zealand region have been little studied, the only important papers being those of COBB (1904), and ALLGEN (1929). Cobb described Miconchus rex (Cobb, 1904) Andrassy, 1958 from 200-1200 feet in Lakes Manapouri and Wakatipu, and Allgen recorded "Mononchus papillatus" Bastian = Prionchulus muscorum (Dujardin) in moss from New Zealand and Campbell Island, and lotonchus trichurus Cobb, I. parazschokkei (Allgen), and Mononchus campbelli Allgen in moss from Campbell Island. The determina- tion of I. trichurus from a single larva is doubtful. The material described in this and succeeding papers was collected by the author, killed by heat, fixed in F.A. 4 : 10, and transferred to glycerine by Baker's method. Mononchus Bastian, 1865 Mononchus campbelli Allgen, 1929 Allgen's inadequate description is based on two poorly fixed distorted larvae from moss on Campbell Island. No precise locality is given, and no type specimens appear to have been kept. ANDRASSY (1958) synonymised M. campbelli with "M. papillatus" of SCHUURMANS STEKHOVEN & TEUNISSEN ( 1938) from the Bel- gian Congo, and tentatively with M. allgeni Meyl, 1957 from Lake Tanganyika. However, c for M. campbelli is 7.2 against 12.9 for M. allgeni. In "M. papillatus" c = 16 for larvae and 11.5 for adults, the dorsal tooth is situated more anteriorly in the stoma and the tail shape differs. Zoogeographically it is unlikely that the same species would occur in the Belgian Congo and on a subantarctic island. No useful purpose is served retaining this doubtful species and I regard M. campbelli as a species inquirenda. Mononchus composticola n. sp. Figs. 1A-J Holotype 9 L = 2.44 mm; a = 33; b = 4.67; c = 9.2; V 1150 12 Allotype 6 L = 3.42 mm; a = 39; b = 4.75; c = 21.5; T = 53. For measurements of paratypes see Table I.
1) At present on study leave from Entomology Division, D.S.I.R., Nelson, New Zealand. 200 W. C. CLARK
O 0 0 0 O G E F J A B F D H
------
Fig. 1. .Mononchus composticola n. sp. A. lateral view of head, B. en face view of lip region, C. stoma at level of tooth apex, D. oesophago-intestinal junction, E. ventral view of vulva, F. lateral view of vulva, G. male tail, H. spicules and gubernaculum, I. supplement, J. female tail. NEW ZEALAND MONONCHIDAE I 201
TABLE I Measurements of Mononchus composticola n. sp. The Pelorus Arthurs. Arthurs Mt. Cook Chateau Tutamoe Br. Waiotapu Pass Pass (females) (males) n. 7 10 12 1 7 36 3 L. (mm) 2.18 2.08 2.17 2.59 2.35 2.33 3.22 (mean) S.D. mm ± 0.323 ± 0.124 ± 0.169 — ± 0.192 ± 0.166 — range 1.76-2.66 1.88-2.29 1.91-2.44 2.59 2.11-2.60 1.83-2.70 3.04-3.51 a 27-38 25-38 33-42 31 30-35 27-36 35-38 b 4.21-5.25 3.9-4.5 3.68-5.05 5.18 4.6-5.0 3.76-4.95 4.5-4.7 c 7.5-10.9 7.2-8.4 7.4-9.8 11.0 8.5-10.7 7.2-9.9 17.8-22.0 a.o. 1) 7-9 10-13 9-14 8 8-11 7-9 — V 45.4-54.2 50.8-54.7 48.5-54.7 47.7 44.8-48.9 48.3-52.0 T. 52.4-57.9 p.o. 1) 7-13 8-12 10-13 12 7-10 5-13 — 1) Anterior and posterior ovaries respectively. Measured specimens from Levin Bush, Hongi's Track, Takaka Hill, and Lake Mahinapua all fell within the range of measurements given above.
Cuticle 2.5 p. thick, with fine, faint annulations only visible under oil immersion in favourable circumstances. No lateral fields. Subcuticle 2.0 p, thick. Body outline tapering anteriorly; lip region not offset. Lips and papillae clairly visible in lateral view. Amphid apertures elliptical in lateral view, situated a little anterior to the apex of the dorsal tooth. Amphid constricted to two-thirds aperture width at a distance equal to aperture width, then expanding again. In en face view lip region a rounded hexagon, symmetrical, all six lips rounded on both edges. Papillae in two rings; six in the inner ring and ten in the outer ring, (two on the sub-ventral lips and one on each lateral lip). Amphid apertures appear as crescentic slits in this view. The abutting edges of the anterior elements of the stoma skeleton elements appear thickened, project outwards, and are coin- cident with the clefts between the subdorsal and lateral lips, and between the subventral lips. At the level of tooth apex the tooth spreads onto the whole of the dorsal stoma wall. In lateral view the rather small stoma occupies half the body width, is attenuated oval in shape, more pointed posteriorly than anteriorly. Ante- rior aperture approximately half the greatest stoma width. Dorsal wall bears a single strong tooth the anterior edge of which is straight or slightly curved, and slopes slightly back from apex. Tooth apex at 6-17 per cent of stoma length. The posterior edge or buttress of the tooth is continuous with the contour of the poste- rior part of the wall. Whole tooth lies within anterior two-fifths of stoma. Ante- rior to the tooth the dorsal wall curves inwards. Outer surface of stoma wall indented in region of tooth. Anterior and posterior ventral elements curve smooth- ly throughout their length. Posterior dorsal element much thickened in anterior half, but thinning towards oesophageal lumen. Anterior two-thirds of stoma sur- 202 W. C. CLARK
rounded by a thin muscle sheath; posterior third embedded in anterior end of the oesophagus. Oesophagus slightly expanded anteriorly about stoma base; narrowing a little to nerve ring at one third of oesophageal length; expanding slightly beyond this in conformity with the body contour, and occupying half the body width. Oesophago-intestinal junction non-tuberculate, (CLARK, 1960a) with a strong sphincter muscle enveloping the funnel-shaped valve. A fairly broad transparent zone is intercalated between oesophagus and sphincter muscle. A conical structure projects into intestinal lumen. Intestine is a simple tube; cells packed with fine granules. Female. Vulva a transverse slit one quarter body-width, with thickened lips. Radiating muscle bands are conspicuous in ventral view. Vagina thick-walled and extending across half the body-width. Uterus bifid; size varies with stage of otigenesis. Ovaries paired, opposed, reflexed through two thirds of the length of the oviduct and uterus. Ovary occupying up to four-fifths of body width. Oocytes in a single row. Usually one or two mature eggs at a time; rarely three. Intestine passes to the left of the anterior and to the right of the posterior ovary. Pre-rectum not demarcated in the female. Rectum straight, length almost equal to an anal- body-width. Tail moderately elongate (five and a half to six times anal-body-width in length), conoid, ventrally arcuate, tip rounded. Caudal glands present; terminal duct absent. Four pairs of lateral cuticular pores distributed as shown in figure 1. Male. Testes paired, opposed, outstretched. Relative development of anterior and posterior testes variable. Sperms numerous, not arranged in any definite pat- tern. Testes nine-tenths as long as vas deferens. Opposite the second supplement the vas deferens enlarges to become the ejaculatory duct, and continues as such to its junction with the cloaca. Pre-rectum as long as ejaculatory duct. Spicules separate, stout, arcuate, more slender at tips. Upper portions of spicules embedded in a muscular sheath. Gubernaculum broad, U-shaped, strap-like, almost encircling the spicules. Each arm of the U with a thickened supporting ridge run- ning laterally from the posterior face near the base of the U to near the anterior edge of the tips of the lateral processes. Midventral supplements 12, not echinu- late, mostly mammiform, but the mammiform protuberances not well developed at the ends of the series. An adanal pore is present. Anterior to the supplements are a number of simple cuticular pores. Tail short, two and a half times anal-body-width, conoid, ventrally arcuate, tip rounded. Caudal glands present, terminal duct absent. Caudal pores as shown in figure 1 G. Specific differentiation. M. composticola forms with M. major• Cobb, 1893, M. mesadenus n. sp., and M. gerlachei de Man, 1904 a closely related group of southern species. The only similar European species is M. kastrolli Altherr, 1958 which is readily separated from this species-group by the short tail (c = 33 or more), the presence of bifid spicules, and notched lateral accessory pieces in the NEW ZEALAND MONONCHIDAE I 203
male. A new figure of the spicules etc. of M. kastrolli (drawn from paratypes supplied by Dr. Altherr) is provided (fig. 2). Of the New Zealand species, M. composticola is similar to M. mesadenus from which it is separated by the more slender female tail; c is usually within the range of 7-9.5 (mesadenus c = 10- 16.5) and the presence of vulval gland ducts opening through the cuticle anterior and posterior to the vulva in mesadenus, but not in composticola. Males may be
Fif. 2. Mononchus kastrolli Altherr, spicule, gubernaculum and lateral accessory piece.
distinguished by the supplements which number twelve in composticola; nine in mesadenus, and are echinulate only in the latter. Mononchus composticola, major, mesadenus and gerlachei may be separated by the use of the following keys: Key to males: 1. Lateral accessory pieces rounded at tip M. gerlachei Lateral accessory pieces absent 2 2. Supplements echinulate 3 Supplements not echinulate, twelve M. composticola 3. Nine supplements; sixteen cephalic papillae M. mesadenus Twelve supplements; thirty-two cephalic papillae M. major Key to females: 1. Glands present near vulva 2 Glands not present near vulva M. composticola 2. Terminal caudal gland duct present 3 Terminal caudal gland duct absent M. mesadenus 3. Sixteen cephalic papillae, (Danco Land and Possession Island, Antarctic region (de Man, 1904, Steiner, 1916)) M. gerlachei Thirty-two cephalic papillae (Australia & Tasmania (Cobb 1893, 1917) M. major Type slides. Holotype, allotype and paratype slides in nematode collection, En- tomology Division, D.S.I.R., N.Z. Paratypes also at Nematology Dept. Rotham- sted Experimental Station. Slide nos. 143/4/1-2.
204 W. C. CLARK
Type locality. Rough Creek, Arthurs Pass, N.Z., from leaf litter of Nothofagus cliffortiodes Oerst. forest with Coprosma Forst spp., Nothopana.x simplex Seem., Griselinia littoralis Raoul, and Blechnum pennamarina Kuhn, altitude 765 metres; soil Haast fine sandy loam. Other localities. (a) South Island; Takaka Hill in Nothofagus fusca Oerst. forest; Lake Mahinapua Forest Reserve in litter of Quintinia acutifolia T. Kirk — Jr einmannia racemosa Linn. f. forest; Pelorus Bridge in litter of Podocarpus s pi- catus R. Br. — Beilschmiedia Tawa Benth. & Hook. f. forest; Governors Bush, Mt. Cook in Nothofagus Menziesii Oerst. forest litter. (b) North Island: Levin Bush in litter of Knightia excelsa R. Br. — Beilschmiedia Tawa Benth. & Hook. f. forest; Tongariro National Park, near Chateau, in Nothofagus cliffortiodes Oerst. — Griselinia littoralis Raoul forest litter; Tutamoe in litter of Beilschmiedia Tawa Benth. & Hook. f. — Dacrydium cupressinum Soland. forest. Remarks. This species has been found only in the litter of indigenous forests in areas with a rainfall in excess of 40 in. per annum, though most localities approach more closely to 100 in. per annum. Neither the soil underlying the litter nor the species composition of the forest appear important in determining distribution. M. cornposticola may be equally abundant in small-leaved mor type, Nothofagus litter and in the broad-leaved, mull type Beilschmiedia forest. The association with forest litter suggested the specific epithet. A parasitic sporozoan, Legerella sp. was found in a specimen from Arthurs Pass.
Mononchus mesadenus n. sp. Figs. 3A-K. Holotype L = 3.37 mm; a = 40; b = 4.45; c = 12.4; V = 11 54 10 Allotype d L = 3.26 mm; a = 40; b = 4.34; c = 20.5; T = 53. For measurements of paratypes see Table II. Cuticle 3.5 tc thick, smooth, very faint obsolescent transverse striae occasionally seen under oil immersion. Lateral fields not present. Subcuticle 2.5 p. thick, faintly annulated. Lip region not offset; lips and papillae clearly visible in lateral view. Amphid apertures appear circular in lateral view, are one sixth as wide as the lip region, and narrow rapidly. Amphids are situated near the anterior limit of the sclerotized stoma and immediately posterior to the lateral papilla. In en face view the lip region is bilaterally symmetrical, an elongate hexagon. Lips six, equal, inner edge bluntly rounded; outer edge slightly angled. Papillae in two rings, an inner ring of six and an outer ring of ten. Inner papillae flanked on either side by a rounded eminence. In this view the anterior edge of the stoma resembles that or M. composticola, but the dorsal tooth does not spread onto the stoma wall to the same extent. Laterally the stoma appears heavily sclerotized, twice as long as broad, oval in shape; fairly rounded posteriorly, and occupies just over half the body width. Anterior aperture half as wide as the greatest stoma width. Stoma walls with fine transverse striae. Dorsal tooth apex occurs at 7-16 % of the stoma length. Anterior edge of the tooth straight or slightly curved; sloping a little back
NEW ZEALAND MONONCHIDAE I 205
Fig. 3. Mononchus mesadenus n. sp. A. lateral view of head, B. en face view of lip region, C. oesophago-intestinal junction, D. ventral view of vulva, E. female reproductive organs, F. vulval region showing gland cells and ducts, G. male tail, H. supplement, I. tip of male tail, J. spicule and gubernaculum, K. female tail. 206 w. C. CLARK
TABLE II Measurements of Mononchus mesadenus n. sp. Mt. Females Messenger The Chateau Tutamoe Kiripaka Takaka Hongi's Track n 9 6 6 2 2 1 L (mm) 3.17 3.35 3.09 3.78 3.32 2.49 (mean) S.D. (mm) ± 0.183 ± 0.227 ± 0.128 — range 2.87-3.44 3.08-3.72 2.94-3.26 3.77-3.79 3.28-3.36 2.49 a 35-40 35-38 32-39 38 35-39 33 b 3.99-6.09 4.10-4.72 4.26-4.45 4.91-4.93 4.56-4.82 4.89 c 10.5-13.1 10.143.1 10.2-12.6 13.8-13.9 13.6-16.4 15.6 a.o. 9-15 7-15 8-15 11-13 9-11 7 V 47.2-56.0 51.0-53.5 51.3-55.3 51.5-52.2 54.4-55.8 51.8 p.o. 8-13 7-13 8-16 11 12 9 Mt. Males Messenger The Chateau Tutamoe Kiripaka Rimu Collingwood n 13 7 10 1 2 1 L (mm) 3.10 3.09 2.94 3.71 3.00 2.70 (mean) S.D. (mm) ± 0.185 ± 0.225 ± 0.177 — — — range 2.61-3.35 2.94-3.62 2.65-3.20 3.71 2.78-3.23 2.70 a 31-40 35-40 34-41 39 32 36 b 4.15-4.55 3.96-4.26 3.99-4.45 4.71 4.02-4.03 3.88 c 16.0-20.8 15.0-18.1 14.6-20.1 22.3 17.0-18.3 22.3 T 53.1-57.2 41.4-62.4 38.8-48.2 58.7 40.1-54.8 53.2
from apex. Posterior edge slopes smoothly back and joins stoma wall without any re-entrant angle. Opposite the dorsal tooth the outer surface of the dorsal stoma wall is slightly indented. Anterior to the tooth the wall curves sharply in- wards. Lower three-fifths of the ventral wall almost straight, anterior portion curving slightly inwards. Of the posterior elements the dorsal one is thickest anteriorly; both thin towards the oesophageal lumen. Anterior seven-tenths of stoma surrounded by a thin muscular sheath; posterior part embedded in anterior end of oesophagus. In the stomal region is a pair of subventral, subdorsal, and median cuticular pores. Oesophagus narrows slightly to the nerve ring which occurs at one third of the oesophagus length, and thereafter swells a little generally occupying half the body width. Oesophago-intestinal junction non-tuberculate. Transparent zone be- tween the oesophagus and sphincter muscle often wide (one-third as thick as sphincter muscle). Funnel-shaped valve obscure in all specimens. Intestine packed with dark granules. Female. Vulva a transverse slit with thickened lips. Vagina with thick muscular walls, extending half way across the body. Uteri paired, outstretched. Interposed between uterus and oviduct is a thick-walled glandular structure and a sphincter muscle similar to that recorded by GOODEY (1942) in Anatonchus tridentatus NEW ZEALAND MONONCHIDAE I 207
and Mylonchulus brachyuris. Ovaries paired, reflexed through up to one-third of the length of the oviduct and uterus. Ovaries occupying almost half the body width. One or two mature eggs in the uteri at once. Near the vulva are a number of pores through the cuticle which appear to be connected with small gland cells. The largest of these have small cuticular mounds about the orifices of the ducts; the smaller ones do not. These structures tend to be arranged in ventro-median pairs, but exceptions are numerous. Some ducts are always present, but the number and position of both types of duct is variable. Simple body pores are present over the whole of the animal, but the papilliform pores are restricted to the vicinity of the vulva. The intestine passes to the left of the anterior, and to the right of the posterior ovary. No pre-rectum. Rectum slightly arcuate, equal to anal-body-width. Tail short, equal to four and a half times the anal-body-width; conoid, ventrally arcuate tip rounded. Caudal glands present; no terminal duct. Paired lateral cuticular pores present, often arranged as in figure 3 K, but there appears to be considerable variation. Males. Testes paired, opposed, outstretched, sperms abundant, not arranged in any definite pattern. Vas deferens five-sixths of testicular length, dilating opposite the first supplement to become the ejaculatory duct and discharge into the cloaca. Also opposite the first supplement the intestine narrows to form the prerectum. Spicules separate, arcuate, thinning towards the tips with a median thickened rib in the distal two thirds. Total length of spicules equal to one and two-thirds anal-body-widths. Gubernaculum U-shaped, strap-like, almost encircling the spi- cules. Each arm of the U with a thickened anterior edge. Supplement nine, the middle seven mammiliform echinulate; first and anal supplements with low mounds rather than papillae. Anterior to the supplements is a series of body pores. In ventral view the basal echinulate portions of the supplements are seen to consist of two opposed crescentic swollen ridges. Tail shorter than female; equal to two anal-body-widths, conoid, ventrally ar- cuate, with caudal glands and terminal duct. Paired lateral cuticular pores as shown in figure 3 G. Specific differentiation. See under i14. corn posticola. Type material. Holotype, allotype, and paratype slides in the nematode collection of Entomology Division, D.S.I.R., N.Z. Paratypes also at Nematology Dept., Rothamsted Experimental Station. Slide nos. 143/5/1-2. Type locality. Mt. Messenger, Taranaki, N.Z., N.Z.M.S. 1, N. 100, 146126, in Olea Cunninghamii Hook. f., Vitex lucens T. Kirk, Shawia paniculata Forst., Bra- chyglottis repanda Forst. forest litter; altitude 200 metres. Other localities: (a) South Island: Collingwood from litter in a very damp spot in a Rhopalostylis sapida \Vend'. & Drude grove; Takaka Hill, in litter of Notho- fagus fusca Oerst. forest; Rimu State Forest (Thuya plicata Don. + regenerating natives) surface liverworts and mosses, (b) North Island: Tongariro National Park, near the Chateau in Nothofagus cliffortiodes Oerst. — Griselinia littoralis
208 W. C. CLARK
Fig. 4. Mononchns propapillatus n. sp. A. lateral view of head, B. en face view of lip region, C. stoma at level of tooth apex, D. oesophago-intestinal junction, E. ventral view of vulva, F. female reproductive structures, G. female tail, H. male tail.
NEW ZEALAND MONONCHIDAE I 209
Raoul forest litter; Hongi's Track, in litter of Beilschmiedia Tawa Benth. & Hook. f. — Knightia excelsa R. Br. — Podocarpus Totara D. Don forest; Kirkpaka in litter of Beilschmiedia Taraire Benth. & Hook. f. — Vitex lucens T. Kirk — Corynocarpus laevigata Forst. forest; Tutamoe, from mosses and liverworts off tree trunks in Beilschmiedia Tawa Benth. & Hook. f. — Dacrydium cupressinum Soland. forest. Remarks. This species, like M. composticola is found in native forests, but is associated with the cryptogamic flora as well as with the litter zone, and is more abundant in the North Island than in the South Island. The specific name refers to the glands about the median vulva (mes = middle, adenus = a gland). Females collected in April 1958 had spermatozoa in the uterus and oviduct.
Mononchus propapillatus n. sp. Figs. 4A-H.
Holotype L = 1.16 mm; a = 22; b = 3.5; c = 12.6; V 24 61.5 14. Allotype 6 L = 1.10 mm; a = 32; b = 3.5; c = 11.5; T = 39. For measurements of paratypes see Table III. Cuticle smooth, without striations, 2 µ thick. Lateral fields not detected in either sex. Subcuticle 1.5 µ, thick. Head offset by a moderate constriction, lips distin- guishable in lateral view. Amphid opening slit-like, situated at the level of the dorsal tooth apex, and immediately posterior to the outer lateral papilla. Amphid narowing to half aperture width at a distance equal to amphid width; amphid obscure beyond this point. In en face view lip region hexagonal, symmetrical; all six lips similar, rounded on both edges. Papillae in two rings; an inner ring of eighteen, three on each lip arranged in a straight line across the lip, and an outer ring of fourteen, three on each of the submedian lips and one on each of the laterals. Amphid apertures crescentic in this view. Anterior rim of sclerotized stoma conspicuous; the sutures between the three parts coincide with the clefts between the subdorsal and lateral lips, and between the subventral lips. At the level of the dorsal tooth apex the stoma is rather oval in cross section, and is slightly indented ventrally. This inden- tation bears the ventral ridge seen in lateral view. Near its apex the tooth spreads over the whole of the dorsal wall of the stoma. In lateral view the heavily sclerot- ized stoma occupies half the body width, is roughly oval in shape, but rather blunter anteriorly than posteriorly. The anterior aperture is circular and approxi- mately one third of the greatest stoma width. The dorsal wall bears the large, single tooth whose anterior edge is straight and which slopes slightly posteriorly from the apex. Posterior edge or buttress of the tooth joins the lateral wall slightly anterior to the mid point of this wall. In the region of the tooth the outer surface of the wall is slightly indented. Ventral wall curves smoothly throughout its length, and from the posterior limit of the anterior element to a point nearly TABLE III Measurements of Mononchus propapillattis n. sp. females
Waitaanga Kumara Levin Mt. Cook Saddle Beach Kiripaka Waimangu Mangatere Kerikeri Craigielachie Takaka Tikipunga Bush n 24 13 12 8 7 6 5 5 6 3 1 L (mm) 1.15 1.57 1.21 1.02 1.09 1.27 0.89 1.19 1.01 1.27 1.03 (mean) S.D. ± 0.060 ± 0.132 ± 0.058 ± 0.057 ± 0.078 ± 0.089 ± 0.037 ± 0.024 ± 0.051 ± 0.041 — (mm) range 1.01-1.71 1.39-1.78 1.12-1.32 0.93-1.11 0.95-1.18 1.21-1.38 0.84-0.93 1.14-1.21 0.93-1.07 1.08-1.38 1.03 a 23-33 27-34 24-36 25-31 27-28 24-29 26-29 25-30 24-28 29-30 21 b 3.24-3.81 3.4-3.98 3.30-3.71 3.21-3.45 3.00-3.44 3.52-3.89 3.18-3.23 3.34-3.47 2.95-3.41 3.48-3.87 3.62 c 11.9-16.5 10.1-12.8 13.2-18.9 10.7-13.3 11.2-13.3 13.8-15.7 10.3-11.6 14.8-17.4 12.1-13.8 12.8-15.0 10.7 a.o. 8-16 7-19 10-14 8-15 7-13 8-12 10-13 10-16 9-14 10-11 12 V 57.7-62.9 58.6-69.1 61.1-62.6 61.2-64.1 59.7-63.4 59.5-65.5 60.2-61.9 61.8-64.0 57.8-63.3 61.0-61.7 61.6 p.o. 10-16 8-16 8-12 9-12 7-12 7-20 8-13 9-15 10-15 10-11 18 NEW ZEALAND MONONCHIDAE I 211 opposite the tooth apex is a low untoothed ridge. The posterior elements make up the base of the stoma; the dorsal element is greatly thickened anteriorly, but the ventro-lateral elements are not. All three posterior elements are continuous with the cuticular lining of the oesophagus. Anterior three-quarters of stoma surround- ed by a muscle sheath; posterior quarter embedded in the fore end of the oeso- phagus. Oesophagus slightly expanded anteriorly, then narrowing a little to the nerve ring at one third its length; expanding slightly beyond this in conformity with the general body contour, and occupying half the body width. Oesophago-intestinal junction typical of the genus, as shown in figure 4 D. Intestine a simple tube; cells packed with fine granules. Female. Vulva a transverse slit with thickened lips which make it conspicuous even in lateral view. Vagina thick-walled and extending one third of the body- width. Uteri bifid, size very variable with the stage of development of the eggs. Ovaries paired, opposed and reflexed through three-quarters of their length. Ovaries almost three quarters as wide as the body, ova in a single row within each ovary. Usually only one mature egg at once, rarely two. (Material collection in February). Intestine passes to the left of the anterior and to the right of the poste- rior ovary. No prerectum in female. Rectum straight. Tail conoid, ventrally arcuate, two and a half times anal body width in length, tip rounded. Caudal glands present, terminal duct absent. Caudal cuticular pores not seen. Males. Testes paired, outstretched in opposite directions; anterior testis five- sixths as long as posterior testis; sperms numerous, not arranged in any definite pattern. Vas deferens seven-eights of testicular length. From a point opposite the second supplement the vas deferens swells to become the ejaculatory duct which opens into the cloaca. Pre-rectum as long as ejaculatory duct. Spicules long, arcuate, moderately slender, upper half embedded in a muscular sheath. Gubernaculum large, complex, consisting of a median dorsal portion from which arise two broad strap-like lateral processes which curve around the spicules. From the outer surface of each lateral process arises a ventrally directed accessory piece which is bifid at the tip. Supplements, nine papilliform, and one adanal without a papilla. The anterior three more widely spaced than the remainder. Tail similar to female but tip more pointed. Caudal papillae, one dorsal pair at one-third of tail length and one lateral pair at threefifths of tail length. Differential diagnosis. Mononchus propapillatus differs from all other species in the genus, except M. papillatus Bastian in the possession of an untoothed ventral ridge. It is close to M. papillatus from which it is distinguished on male characters; viz. the presence of lateral accessory pieces; a gubernaculum with curved lateral processes which curve around the lateral accessory pieces and the spicules, and only ten supplements, of which the adanal member is not papilli- form. M. papillatus has no lateral accessory pieces, the gubernaculum is simple, without lateral processes, and lies wholly above the spicules; the supplements are 212 W. C. CLARK twelve to sixteen in number and uniform in type. The lips of propapillatus are rounded, and the stoma oval in cross section, but in papillatus the lips are angular, and the stoma squarish. The females of M. pro papillatus are so similar to those of M. papillatus that I hesitate to erect a new species, but in view of the dissimilarity of the males there is no alternative as there is no doubt that they are correctly associated with the females. New Zealand has been isolated from other land masses since Cretaceous times and, on virgin sites, it is reasonable to expect slightly different forms. There is no reason why specific differentiation should not go further in one sex than in the other. There is no evidence of male dimorphism as found in the Acari (ANDRE, 1949) and the Opiliones (FORSTER, 1954) as only one type of male is known for each species. Type slides. Holotype, allotype and paratypes are in the nematode collection, Entomology Division. Paratypes also at Nematology Department, Rothamsted Experimental Station; Slide nos. 143/6/1-1. Type locality. Governor's Bush, Mount Cook, in Nothofagus Menziesii Oerst. forest with Podocarpus Hallii T. Kirk., Phyllocladus alpinus Hook. f. and Coprosma spp. Forst. from surface three inches of litter and soil. Soil type: Haast fine sandy loam (a semi-mature podzol derived from greywacke and schist). Height 810 metres. Other localities. (a) South Island: Takaka Hill in Nothofagus fusca Oerst. for- est; Whangamoa Hill in reverting grassland; Kumara Beach, Trifoliunz repens L. — Hydrocotyle sp. L. dominant grassland; Charleston Beach in Lotus uliginosus Schkuhr.; Ross in Anthoxanthum odoratum L. — Trifolium repens L. pasture; Cape Foulwind in Agrostis stolonifera L. — Holcus lanatus L. pasture; Utopia Road, Westport in Anthoxanthum odoratum L. — Cynosurus cristatus L. pasture; Granity in Agrostis stolonifera L. — H. lanatus L. pasture; Pelorus Bridge in Podocarpus spicatus R. Br. — Beilschmiedia Tawa Benth. & Hook. f. forest; Craigielachie, Dactylis glomerata L. — Agrostis tenuis Sibth. pasture; Cass in Agrostis tenuis Sibth. — Anthoxanthum odoratum L. grassland; Waikari — Cul- verden in Festuca novaezealandiae Cockayne — Agropyrum scabrum Beauv. grass- land. (b) North Island: Levin Bush Knightia excelsa R. Br. — Beilschmiedia Tawa Benth. & Hook. f. forest; Waverly in Lolium perenne L. — Trifolium repens L. pasture; Waitaanga Saddle W'einmannia racemosa Linn. f. — Brachyglottis repanda Forst. — tree fern forest; Mangatere, Paspalum dilatatum Poir dominant pasture; Wharekohe, 2 year old Lolium perenne L. — Trifolium repens pasture (previously heathland type vegetation); Kiripaka in Beilschmiedia Taraire Benth. & Hook. f. — Vitex lucens T. Kirk forest; Tikipunga in Paspalum dilatatum Poir — Lotus hispidus Desf. — Trifolium repens L. pasture; Kerikeri in Low Leptospermum scoparium Forst. — Hakea acicularis R. Br. — Cassinia fulvida Hook. f. heath; Waimangu under Pteridium esculentum Hook. f., Rubus sp. L. (blackberry), Festuca arundinacea Schreb. Remarks. This species is very widespread in New Zealand and its distribution NEW ZEALAND MONONCHIDAE I 213 seems little influenced by factors such as soil type, vegetation cover, or climate. The specimens from Kerikeri, however, where the soil is particularly barren, are smaller than those from other localities. lotonchus parazschokkei (Allgen) is also small at this site. Prionchulus muscorum (Dujardin, 1845) Chitw. & Chitw., 1937 For synonymy see CLARK, 1960b. Arthurs Pass 1 L = 2.8 mm; a = 34; b = 4.25; c = 9.27; V 11 62.5 12 stoma 47 1.L. Mt. Cook 1 L = 1.715 mm; a = 32.73; b = 3.81; c = 16.52; V 12 62.1 13 stoma 37 tc. Waimungu 1 L = 1.95 mm; a = 30; b = 4.19; c = 15.9; V 11 65.1 12 stoma 38 IL. Wharekohe 1 L = 1.68 mm; a = 35; b = 4.02; c = 17.3; V 9 66.3 7 stoma 36 µ. Remarks. The measurements given above lie for the most part within the limits of variation given for this species by CLARK (1960b) for British specimens. The most important divergence is that for tail length in the Arthurs Pass specimen where c = 9.27 which indicates a much longer tail than is usual in European specimens. I hesitate to separate this form on the basis of a single specimen. Otherwise it is indistinguishable from European specimens. In the specimens from the other localities in New Zealand the denticulations of the ventral ridges are less well developed than in British specimens. Other locality. Nelson, Entomology Division compost heap, larvae only.
ZUSAMMENFASSUNG Neu-Seeliindische Mononchiden (Enoplida, Nematoda) I. Die Gattungen Mononchus Bastian und Prionchulus Cohb Mononchus composticola, M. mesadenus, und M, propapillatus n. spp. werden beschrieben, Prion- chulus muscorum (Dujardin) wird aus Neu-Seeland erwahnt. M. campelli AlIgen 1929 ist als species inquirenda anzusehen. M. composticola und Al. mesadenus werden mit Al. gerlachei de Man 1904 und M. major Cobb 1893 vereinigt. Durch den angegebenen Schlassel konnen sie voneinander getrennt werden.
REFERENCES ALLGgN, C. (1929). Uber einige freilebende Moosnematoden, Nyt Mag. Naturv. 67, 211-230. ANDRASSY, I. (1958). "Ober das System der Mononchiden (Mononchidae Chitwood, 1937; Nema- toda), Ann. Hist.-nat Mus. hung. n.s. 9. 50, 151-171. ANDRn, A. (1949). Ordre des Acariens (Atari Nitsch, 1818) Traite de Zoologie, Paris. 6, 794-892. CLARK, W. C. (1960a). The oesophago-intestinal junction in the Mononchidae (Enoplida, Nema- toda), Nematologica, 5, 178-183. - (1960b). Redescription of Mononchus truncatus Bastian, M. papilla/us Bastian, and Prion- chulus (Dujardin) (Enoplida, Nematoda), Nematologica, 5, 184-198. COBB, N. A. (1893). Nematodes, mostly Australian and Fijian, Macleay Memorial Volume, Linn. Soc. N.S.117., 1-59. - (1904). Free-living fresh-water New Zealand nematodes, Proc. Camb. phil. Soc., 12, 363-374. -- (1917). The Mononchs (Mononchus Bastian, 1865), a genus of freeliving predatory ne- matodes, Soil Sci., 1, 431-486. 214 CLARK, NEW ZEALAND MONONCHIDAE I
FORSTER, R. R. (1954). The New Zealand Harvestmen (sub-order Laniatores) Canterbury [N.Z.] Mus. Bull., 2. 329 pp. GOODEY, T. (1942). Observations on Mononchus tridentatus, M. brachyuris and other species of the genus Mononchus, I. Helm. 20, 9-24. DE MAN, J. G. (1904). Nematodes Libres, Resultats du Voy. du S. Y. Belgica, 1897-99, Zoologie, 1-55. ScHuuRmANs STEKHOVEN, J. H. & TEUNISSEN, R. J. H. (1938). Nematodes libres terrestres, Exp/. du Parc National Albert Mission G. F. de Witte 1933-1935, 22, 1-229. STEINER, G. (1916). Beitrage zur geographischen Verbreitung freilebender Nematoden, Zool. Ann., 46, 311-347.
Received for publication: July 1, 1960 Nematologica 5 (1960): 275-284. Leiden, E .J. Brill
7. THE MONONCHIDAE (ENOPLIDA, NEMATODA) OF NEW ZEALAND III. A REVIEW OF THE GENUS COBBONCHUS ANDRASSY, 1958 WITH DESCRIPTIONS OF NEW SPECIES
BY
W. C. CLARK Rothamsted Experimental Station, Harpenden, Herts., England 1)
ANDRASSY (1958) erected the genus Cobbonchus for three species, M. paha- tris Cobb, M. radiatus Cobb and M. teres Cobb, which COBB (1917) had referred to Mononchus Bastian. Cobbonchus is characterised by the possession of an anterior dorsal tooth and two posterior subventral teeth. None of these species was fully described. C. radiatus and C. teres are based on "a single young specimen" and a "single more or less shrunken specimen" respectively. Cobb did not remark on the rounded head of C. pa/ustris which is quite unlike that of any other mononchid. Miss E. M. Buhrer (in lilt.) considers it unlikely that the holotypes of these species still exist. When Cobb based a species on a single specimen it was usually beheaded or sectioned. Many were mounted in glycerine jelly which later proved unsatisfactory. However, Miss Buhrer has supplied photographs of Cobb's ori- ginal drawings, including unpublished drawings of the tails which are reproduced here in figs. 1-3. From these figures and Cobb's description I have compiled the fuller descriptions given below. Since Andrassy's work appeared, more information has become available about the genus Cobbonchus, which is redefined below.
Cobbonchus Andnissy, 1958 Emend. Mononchidae. Lip region scarcely or not offset. Stoma moderately large, about twice as long as broad, with three anteriorly directed teeth. Dorsal tooth larger than, and anterior to subventral teeth. Amphids small to moderate, transverse, slit like. Ovaries paired or single. When single either the anterior or posterior ovary may be suppressed and represented by a uterine sac 2 ). Vulva post-median, vagina often muscular. Oesophago-intestinal junction non-tuberculate (CLARK, 1960). Testes paired, opposed, outstretched. Spicules simple, paired, free. Gubernaculum complex. Supplements simple, papilliform, equidistant. Tail in both sexes short,
1) At present on study leave from Entomology Division, D.S.I.R., Nelson, New Zealand. 2) I have a single female of a new species from Stafford, N.Z., which has a posterior ovary and a pre-vulval uterine sac. As this is a most unusual feature, I await more material before describing it. Nematologica V 18 276 W. C. CLARK ventrally arcuate, conoid at first, becoming cylindroid distally. Caudal glands massive, often reaching beyond the anus; ampulla well developed, terminal duct in all known species. Cuticular pores not known in females, on papillae in only known males (C. pounamua n. sp.). Found in wet soil or Sphagnum bogs. Type species (by author's designation): Mononchus palustris Cobb, 1917. The known species of the genus are:
C. chendiodus n. sp. C. pounamua n. sp. C. mauritianus (Williams, 1958) Clark, 1960 C. radiates (Cobb, 1917) Andrassy, 1958 C. palustris (Cobb, 1917) Andrassy, 1958 C. teres (Cobb, 1917) Andrassy, 1958
Cobbonchu.r palustris (Cobb) Andrassy Figs. 1 A-C
Mononchus (Mononchus) palustris Cobb, 1917, p. 154, fig. 18. Mononchus palustris Schneider, 1937, p. 49, fig. 6a-b. Cobbonchns palustris Andrassy, 1958, p. 161 Female (after Cobb) L 1.4 mm; a 37; b 3.33; c 33.3; V 62. Lip region not offset, head rounded. Papillae in two rings of six each. Amphid aperture small, transverse, at level of dorsal tooth apex. Stoma large, almost twice as long as broad, parallel-sided. Stoma wall indented in region of teeth, base broad. Dorsal tooth apex at 32 per cent of stoma length; subventral tooth apices at 57 per
A
Fig. 1. Cobbonchus palustris. A. lateral view of head; B. female tail; C. tail tip. (All after Cobb). cent, posterior fifth of stoma embedded in anterior end of oesophagus. Nerve ring at 8 per cent of body length. Intestine 12-15 cells in girth. Ovaries paired, rather small, tapering, eight to ten oocytes in each. Eggs elongated, twice as long as body width. Rectum straight, length equal to 0.7 of anal-body-width. Tail short, ventrally arcuate, rather conoid. Caudal glands broad, saccate; ampulla large, duct terminal. Recorded by Cobb from a white cedar swamp, Jefferson County, Wisconsin, U.S.A. MONONCHIDAE OF NEW ZEALAND III 277
Cobbonchus radiatus (Cobb) Andrassy Figs. 2 A-B Mononchus (Mononchus) radiatus Cobb, 1917, p. 154, fig. 17. Cobbonchus radiatus Andrassy, 1958, p. 161. "Young specimen" (after Cobb) L 0.8 mm; a 35; b 3.33; c 20; V 74 Lip region offset by a broad shallow constriction. Papillae in two rings, an inner one of six and an outer one of ten. Amphid aperture a small crescentic slit at level of dorsal tooth apex. Stoma large, almost twice as long as broad (figured specimen appears a little distorted). Dorsal tooth apex at 24 per cent of stoma length; subventral tooth apices at 64 per cent. Cobb's figures show two unusual structures posterior to the stoma base which I am unable to explain. Nerve ring at 9 per cent of body length. Genital organs apparently paired and symmetrically
Fig. 2. Cobbonchus radiatus. A. lateral view of head; B. female tail. (Both after Cobb). reflexed. Rectum almost straight, nearly equal to anal-body-width. Anal lips slightly protuberant. Tail short, ventrally arcuate, conoid. Caudal glands rather slender for the genus, ampulla present, duct terminal. Specimen from "patch of wild cranberries with sphagnum", Cranberry Bog, New Lisbon, New Jersey, U.S.A. Remarks. Cobb's sketches include an outline from which the measurements were taken. This shows the anterior and posterior limits of the reproductive system, indicating that the specimen may have been a young adult female. Cobbonchus teres (Cobb) Andrassy Figs. 3 A-B Mononchus (Mononchus) teres Cobb, 1917, p. 155, fig. 19. Cobbonchus teres Andrassy, 1958, p. 161. "Young specimen" (after Cobb) L 0.6 mm; a 26; b 2.86; c 16.5; V 60 Lip region not offset, head squarish. Papillae in two rings of six each. Amphid apertures small crescentic slits at level of dorsal tooth apex. Stoma large, broad, almost barrel-shaped. Dorsal tooth apex at 27 per cent of stoma length; subventral tooth apices at 65 per cent. Posterior fifth of stoma embedded in anterior end of oesophagus. Nerve ring at 8 per cent of body length. Rectum almost sigmoid,
278 W. C. CLARK length a little less than anal-body-width. Anal lips protuberant. Tail strongly arcuate, conoid. Caudal glands elongated, ampulla conspicuous, one fifth as long as tail, duct terminal. Remarks. Cobb noted "description prepared from a single, more or less shrunk- en specimen found in the sphagnum of a pot in which blueberry plants were being cultivated".
A
Fig. 3. Cobbonchus teres. A. lateral view of head; B. female tail. (Both after Cobb).
Cobbonchus mauritianus (Williams) Clark Figs. 4 A-C Mononchus mauritianus Williams, 1958, p. 5-6, figs 5 & 6. Cobbonchus mauritianus Clark, 1960, p. 182. Measurements ? (after Wiliams) L 1.1-1.3 mm; a 32; b 3.16; c 24.4; V 63.2 Cuticle 1 p. thick, smooth, no lateral fields; subcuticle 1 kt thick. Lip region truncate, slightly offset. Body tapering gradually towards head. Papillae in two rings, inner one of six, outer of ten papillae. Amphid aperture of moderate size,
Fig. 4. Cobbonchus mauritianus. A. lateral view of head; B. female tail; C. posterior branch of female reproductive system. a transverse slit situated a little anterior to dorsal tooth apex. Stoma parallel-sided, large, almost twice as long as wide. Dorsal tooth apex 2 3-24 per cent of stoma length; subventral tooth apices at 53-57 per cent. Posterior sixth of stoma em- bedded in anterior end of oesophagus. Oesophagus narrowing a little from stoma base to nerve ring at 23 per cent of its length, then expanding gently to three- MONONCHIDAE OF NEW ZEALAND III 279 quarters body-width at the widest part. Oesophageal gland ducts occur at 39, 73 and 94 per cent of oesophageal length. Oesophago-intestinal junction non-tuber- culate. Conical structure on posterior face of sphincter muscle prominent in my specimen. Vagina a thick walled tube with a sphincter muscle, but without radiat- ing muscle fibres. Uteri and oviducts paired, outstretched; ovaries short reflexed through half length of oviduct and uterus. No prerectum. Rectum straight, almost equal to anal-body-width. Anal lips prominent. Tail short, ventrally flexed, conoid at first, then cylindroid. Caudal glands and ampulla large, prominent. Terminal duct slightly dorsal. No cuticular pores seen. Remarks. The above description was prepared from a single paratype female kindly supplied by Mr. J. R. Williams. C. nzauritianus differs from C. palustris (Cobb) in the shape of the head, the position of the teeth, and the bulbous anal region, but not in the shape of the tail as suggested by WILLIAMS (1958). Wil- liams has informed me (in litt.) that the soil on Plaine Sophie, Mauritius where these specimens were collected is very wet, indicating that this species, like all others in the genus, has a preference for wet situations.
Cobbonchus chauliodus n. sp. Figs. 5 A-D Holotype ? L 3.28 mm; a 51; b 3.12; c 40.6; V 19 69.9 Cuticle 1.5 p. thick, smooth except on cylindroid part of tail where it is annu- lated, no lateral fields. Subcuticle 2 µ thick. Lip region slightly offset. Papillae in two rings; inner ring of six and outer ring of ten. Amphids cup-like, situated a little behind dorsal tooth apex; aperture slitlike. Stoma heavily sclerotized, widest anteriorly, narrowing towards the base. At widest part stoma occupies 70 per cent of body width. Walls inarched anteriorly. Dorsal posterior stoma element appears pyriform in optical section; subventrals appear lenticular, all elements thinning towards oesophageal lumen. Outer surface of stoma with fine transverse striae. Single dorsal tooth massive, apex at 16 per cent of stoma length and reaching almost to centre of stoma, anterior edge straight sloping posteriorly from apex, posterior edge merging with stoma wall near midpoint of stoma. Subventral teeth much smaller than dorsal tooth, apices at 39 per cent of stoma length, anterior edges concave, sloping posteriorly, posterior edges convex. Anterior four-fifths of stoma surrounded by a thin sheath, posterior fifth embedded in anterior end of oesophagus. Oesophagus of uniform diameter from stoma base to nerve ring at one sixth of its length, then expanding a little to occupy three-fifths of body- width. Oesophageal gland ducts occur at 45, 67, and 96 per cent of oesophageal length. Oesophago-intestinal junction non-tuberculate, details obscure, but appears essentially the same as Prionchulus muscorum (Dujardin). Intestine passes to left of reproductive organs. Vulva transverse. Vagina extending across one third of body width, broad. Vulva and vagina surrounded by massive musculature. Uterus prodelphic, doubly reflexed in distal part in holotype (fig. 5), posterior uterus represented by a long post-vulval sac. Sphincter muscle present at uterus-oviduct 280 W. C. CLARK
junction. Ovary rather small, reflexed less than one fifth of the length of oviduct and uterus. Rectum straight, length equal to anal-body-width. Anterior anal lip lobar in form. Tail short, conoid at first with a ventral flexure, after which it is cylindroid with a terminal peg. Caudal glands very large occupying most of the post-anal space. Ampulla well developed, duct terminal. One cuticular pore near end of cylindroid part of tail. Specific differentiation. The large size immediately separates C. chauliodus from all other species in the genus. Other distinguishing features are the massive dorsal tooth, and the single prodelphic ovary. Type slides Holotype and paratype (larva) in nematode collection, Entomology Division, D.S.I.R., Nelson, N.Z. Type locality. Collingwood Pakihi, Nelson, N.Z.M.S.1. S3, 086013, 30 metres, in a gley podsol soil with Cladium teretifolium R. Br., Gleichenia circinata Swartz, Drosera pyginaea DC. and Celmisia gracilenta Hook f.
Fig. 5. Cobbonchus chauliodus. A. lateral view of head; B. oesophago-intestinal junction; C. female tail; D. female reproductive system. MONONCHIDAE OF NEW ZEALAND III 281
Remarks. The name alludes to the large tooth (zocuLoaok = having prominent teeth). Cobbonchus pounamua n. sp. Figs. 6 A-I Holotype (Awatuna) L 2.87 mm; a 44; b 3.68; c 34.4 V 27 68.9 15 Allotype 6 (Awatuna) L 2.87 mm; a 47; b 3.83; c 34.4 T 34.6
Fig. 6. Cobbonchus pounamua. A. lateral view of head; B. en face view of lip region; C. transverse section through stoma at level of dorsal tooth apex; D. oesophago-intestinal junction; E. male tail; F. spicule, lateral accessory piece and gubernaculum; G. optical section through a— a of fig. F; H. female tail; I. female reproductive system. 282 W. C. CLARK
Paratypes d (Awatuna) L 2.72 mm; a 53; b 3.76; c 30.7 T 33.5 (Hokitika) L 2.17 mm, a 46; b 3.46; c 26.8 T 37.8 d (Fairdown) L 2.68 mm; a 46; b 4.0; c 27.9 T 32.2 ? (Reefton) n = 2; L 1.26-1.30 mm; a 38-39; b 2.89-2.90; c 26.1-27.3 V 7 61.3-63.0 9 Cuticle 1.5 a thick with faint, obsolescent annulations sometimes visible under oil immersion. Subcuticle 1.5 p. thick. Lip region not offset; lateral lips more prominent than others. Amphid apertures slit-like, wide, situated a little in front of dorsal tooth apex. In en face view lip region hexagonal, elongated dorso- ventrally. Papillae in two rings, inner ring with eighteen papillae, three on each lip and outer ring of ten. Amphid apertures appear below outer lateral papillae as crescentic slits. At level of dorsal tooth apex the stoma is oval in cross section, with slight thickenings of the abutting edges of its skeletal elements. In lateral view stoma oval, twice as long as broad, in-arched anteriorly and pointed at base, dorsal wall thicker than ventral wall. Dorsal tooth medium sized, extending across less than a third of stoma width, apex at 31-33 per cent of stoma length, anterior edge almost straight and horizontal, posterior edge slightly concave. Subventral tooth apices at 50-55 per cent of stoma length, teeth similar to, but smaller than dorsal tooth. Posterior fifth of stoma embedded in anterior end of oesophagus. Oesophagus narrowing very slightly to nerve ring at a quarter of oesophageal length, then expanding a little to occupy three quarters body width. Oesophageal gland ducts at 52, 68-71, and 95-97 per cent of oesophageal length. Oesophago- intestinal junction non-tuberculate. Intestine, with large dark granules, passes to left of anterior ovary and to right of posterior one. Female. Vulva a transverse slit. Vagina thick and muscular, extending across one-third body-width. Uteri paired, opposed, outstretched, short. Sphincter muscle present between uteri and oviducts. Ovaries reflexed through half length of uterus and oviduct, half as wide as body. No prerectum. Rectum straight, length equal to three-quarters anal-body-width. Tail conoid, ventrally flexed, tip with peg-like process. Annules fairly easily seen on posterior half of tail. Caudal glands massive, extending anteriorly beyond anus, ampulla conspicuous, duct terminal. A single cuticular pore near ampulla on ventral side. Male. Testes paired, opposed, outstretched, sperm numerous. Vas deferens equal in length to testes. Opposite the second supplement vas deferens enlarges to become the ejaculatory duct, and prerectum is marked off from intestine. Spicules paired, free, slender, arcuate, and bluntly rounded at tips. Lateral accessory pieces present. Gubernaculum similar to some lotonchus species; consisting of a solid dorsal part lying mostly behind the spicules from which arise a pair of lateral processes which extend forward on either side of the spicules and lateral accessory pieces and then turn inwards towards each other in front of the spicules. (Figs. 6 F & G). Supplements papilliform 16-18, largest near middle of series, de- creasing in size towards either end. Tail short, conoid, ventrally arcuate, posterior MONONCHIDAE OF NEW ZEALAND HI 283 anal lip prominent. Caudal glands large, ampulla well developed; duct terminal. Cuticular pores prominent; open on tips of papilliform structures like those de- scribed in males of Mylonchulus brachyuris (Biitschli) by GOODEY (1942). The position of the papillae varies from specimen to specimen but is generally as in fig. 6 E. Specific differentiation. Bears a general resemblance to C. palustris but differs from it in head shape, shape of stoma base, number of cephalic papillae and the orientation of the rectum. Type slides. All type slides in nematode collection, Entomology Division, D.S.I.R., Nelson, N.Z. Type locality. Awatuna, Westland, N.Z.M.S.1. S50/51 62 56 72, Ranunculus sp. Hydrocotyle sp., Juncus sp. Holcus lanatus L.; soil, Mahinapua sands (wet podsolic sands). Other localities. Reefton in sphagnum swamp; Hokitika in swampy pasture with Juncus L., Drosera L. etc.; Fairdown in swampy pasture, Westport pakihi, Glei- chenia circinata Swartz, Sphagnum L., Leptospermum scoparium Forst. and Dro- sera L. sp.; Wharekohe Cladiunt teretifolium R. Br., Leptospermum scoparium Forst. and Gleichenia circinata Swartz. Swampy land in all cases. Remarks. The similarity of the male tails of C. pounamua (the only known males in the genus) and those of Mylonchulus brachyuris point to a close affinity between the genera Cobbonchus and Mylonchulus. This suggested affinity is fur- ther supported by the form of the stoma with three anteriorly directed teeth set at two levels, the non-tuberculate oesophago-intestinal junction, and the similar female tails in both genera. The specimens from Reef ton are smaller than those from elsewhere and have a slightly longer oesophagus, but do not differ in other respects. The specific name is derived from the Maori name for the region in which most specimens were collected. I thank the Nematology Section U.S. Dept. of Agriculture, Beltsville, for per- mission to reproduce Cobb's drawings, and Mr. J. R. Williams for the gift of a paratype of C. mauritianus. ZUSAMMENFASSUNG Die Mononchiden (Enoplida, Nematoda) Neu-Seelands 3. Rfickblick fiber die Gattung Cobbonchus Andrdssy 1958 mit Beschreibungen never Arten Die Gattung Cobbonchus Andrassy 1958 wurde neu definiert. Neue Beschreibungen von C. pa/ustris (Cobb), C. radiatus (Cobb) und C. teres (Cobb) wurden aus COBB (1917) und einigen unvertiffentlichten Abbildungen Cobbs zusammengestellt. C. mauritianus wird neu beschrieben. C. chauliodus n. sp. unterscheidet sich von anderen durch seine Grosse, den massiven Dorsalzahn und das einfache, prodelphische Ovar. C. pounamua n. sp. unterscheidet sich von C. palusiris in der Kopfform, der spitzen Mundbasis und der grosseren Anzahl von Kopfpapillen.
REFERENCES ANDRAssY, I. (1958). Ober das System der Mononchiden (Mononchidae Chitwood, 1937; Nema- toda). Ann, hist.-nat. Alus. hung. n.s. 9, SD, 151-171.
284 CLARK, MONONCHIDAE OF NEW ZEALAND III
CLARK, W. C. (1960). The oesophago-intestinal junction in the Mononchidae (Enoplida: Nema- toda). Nematologica 5, 178-183. Coss, N. A. (1917). The Mononchs (Mononchus Bastian, 1865) a genus of freeliving predatory nematodes, Soil Sci,, 1, 431-486. GoosEY, T. (1942). Observations on Mononchus tridentatus, Al. brachyuris and other species of the genus Mononchus. J. Helm., 20, 9-24. WILLIAMS, J. R. (1958). Studies on the nematode soil fauna of sugar cane fields in Mauritius. 1. The genus Mononchus (Trilobidae, Enoplida), Occas. Pap. (1) Afauritius Sugar Ind. Res. Inst. 13 pp. Nernatologica 6 (1961): 1-6. Leiden, E. J. Brill
8. THE MONONCHIDAE (ENOPLIDA: NEMATODA) OF NEW ZEALAND IV. THE GENUS MYLONCHULUS (COBB, 1916) PENNAK, 1953
BY
W. C. CLARK Rothamsted Experimental Station, Harpenden, Herts., England 1) Two new species of Mylonchulus are described. M. arenicolus n. sp. is distinguished by its almost parallel-sided stoma, the arrangement of the subventral denticles and the tail shape. M. obis n. sp. is marked off by the subterminal position of the caudal gland duct in conjunction with the regularly conoid tail and the arrangement of the subventral denticles.
The genus Mylonchulus appears to be cosmopolitan, having been recorded from most countries where free-living nematodes have been studied. Because Mulvey (pers. comm.) has a revision of the genus in the press, I am describing two new species without either reviewing the genus or commenting on the status of other species. A complete list of the Mononchidae recorded to date from the New Zea- land region is appended. This is the last paper in this series (Clark 1960 a-d).
Mylonchulus arenicolus n. sp. Figs. 1 A-D Holotype L = 1.45 mm; a = 29; b = 3.59; c = 31.4; V 1264.7 13 Paratype L = 1.48 mm; a = 31; b = 3.44; c = 29.7; V 1462.7 13 Cuticle (head region) 1 II thick, smooth; subcuticle 1 IL thick; cuticle much thicker on tail. No lateral fields. Lip region scarcely offset. Lips distinct, some- what pointed; papillae six in inner ring and ten in outer ring. Amphid apertures appear as transverse slits in lateral view situated at the level of the dorsal tooth apex. Stoma heavily sclerotized, almost parallel-sided anteriorly, pointed posteriorly, greatest width equal to three-fifths of stoma length, or half body width at this point. Dorsal stoma wall with a massive pointed dorsal tooth; anterior edge con- cave, sloping posteriorly from tooth apex; posterior edge convex, merging with stoma wall near middle of stoma. Tooth apex extending to middle of stoma and situated at 14-19 per cent of stoma length. Posterior dorsal stomal element rather triangular in optical section. Ventral wall similar to dorsal, but bearing 2 small subventral teeth and six rows of denticles arranged across the ventro-lateral stomal elements. Anterior and posterior ventral elements appear fused. Posterior quarter
1) on study leave from Entomology Division, D.S.I.R., Nelson, New Zealand. 2 W. C. CLARK of stoma with fine transverse striae. Posterior third of stoma embedded in slightly swollen anterior end of oesophagus. Oesophagus narrows a little to the nerve ring at one quarter of its length, then expands again, generally occupying two-thirds of the body width. Dorsal and subventral oesophageal gland ducts occur at 50, 63, and 94 per cent of oesophageal length. Oesophago-intestinal junction non-tuber- culate, no transparent zone observed. Intestine usual for the family.
=MO
A
Fig. 1. Mylonchulus arenicolus n. sp. A. head region, B. oesophago-intestinal junction, C. tail of holotype, D. tail of paratype.
Ovaries paired, reflexed. Vulva a transverse slit at about two-thirds of body length. Vagina thick walled, extending across one-third of body width. Uteri out- stretched with a well developed sphincter muscle at junction with each oviduct; spermatozoa occur abundantly on either side of the sphincter. THE MONONCHIDAE OF NEW ZEALAND. IV 3
Tail short, conoid, ventrally arcuate, generally as in figure 1 C, but often as in fig. 1 D. Caudal glands well developed; duct terminal in position. Cuticular caudal pores as shown in figs. 1 C-D. Larvae similar to female. Males unknown, but the abundance of sperm in the females (collected in Fe- bruary) indicates their probable existence.
Specific differentiation. Readily distinguished from the other New Zealand species by the terminal position of the caudal gland duct. M. arenicolus is distin- guished from other species in the genus by its almost parallel-sided stoma, the arrangement of the sub-ventral denticles and the tail shape. It appears to be clo- sest to M. incurvus (Cobb, 1917). Type slides. Holotype and paratypes in Nematode collection, Entomology Di- vision, D.S.I.R., N.Z. Type locality. Kumara Beach, Westland, N.Z.M.S.I., S 50151 741654 in unsta- bilized dune sand about the roots of Desmoschoenus frondosus Banks & Sol.
Mylonchulus ubis n. sp. Figs. 2 A-E Kumara Beach (Holotype) ? L = 1.24 mm; a = 29; b = 3.54; c = 23.1; V = 8 60 11 (Paratypes) 2 ??, L = 1.2-1.23 mm; a = 27-28; b = 3.36-3.49; c = 24.0-24.7; V 6-7 59.5-60 11 Waitaanga Saddle 2 ?? L = 1.07-1.09 mm; a = 30; b = 3.09-3.12; c = 21.5-23.1; V = 63 Kiripaka ? L = 1.10 mm; a = 27; b = 3.31; c = 22.0; V = 13 63.5 12 Reefton P L = 1.22 mm; a = 27; b = 3.51; c = 24.3; V = 7 59 11 Ross P L = 1.2 mm; a = 25; b = 3.49; c = 23; V = 19 60.7 12 Wharekohe P L = 1.31 mm; a = 32; b = 3.79; c = 26.2; V = 8 54 6 Cuticle 1.3 it thick, smooth, no lateral fields; subcuticle 1 p, thick. Lip region scarcely offset, lips well developed. "Inner lips" pointed, "outer lips" rounded. Papillae in two rings, six in the inner and ten in the outer ring. Amphid aperture a transverse slit situated slightly posterior to the dorsal tooth apex, one-fifth as wide as body at this level. Stoma goblet shaped, pointed posteriorly, half as wide as body in this region. Stoma dominated by the large anteriorly directed dorsal tooth whose apex reaches the centre of the stoma, and which occurs at 14-21 per cent of the length of the stoma. Anterior edge of tooth concave, posterior edge convex. Dorsal wall of stoma clearly divided into anterior and posterior elements, but subventral elements appear to be completely fused. Postero-dorsal element triangular on optical section, antero-dorsal element arcuate in outline. Subventral element straighter anteriorly than dorsal element. Subventral denticles in five to seven transverse rows. Posterior subventral denticles not conspicuously larger than the more anterior ones. Posterior part of stoma with fine transverse striae. Poste- 4 W. C. CLARK rior third of stoma embedded in locally expanded anterior end of oesophagus which narrows slightly to the nerve ring at a quarter of its length and then expands slightly in conformity with the body contour, generally occupying two-thirds of the body width. Dorsal and subventral oesophageal gland ducts discharge into the oesophageal lumen at 55, 68 and 93 per cent of the oesophageal length respectively. Oesophago-intestinal junction non-tuberculate with a transparent zone inter- calated between the posterior end of the oesophagus and the sphincter muscle. Intestine typical of the family. Vulva at 54-63 per cent of body length. Ovaries paired, opposed, reflexed,
A
Fig. 2. illylorichulus obis n. sp. A. head region, B. oesophago-intestinal junction, C. vulva, D. female tail, E. reproductive organs. occupying half body width. Oviducts and uteri short, with a sphincter muscle and glandular region at the oviduct-uterus junction. Only one mature ovum in the uterus at a time: there does not appear to be room for more in such a short reproductive tract. Egg length almost twice body width. Vagina with muscular walls extending across one-third of body width. Prerectum absent, rectum straight, length equal to two-thirds anal-body-width. Tail conoid, ventrally arcuate, tip rounded; caudal glands well developed, duct dorsally subterminal. Cuticular caudal pores apparently lacking. Larvae resemble females. Males unknown. THE MONONCHIDAE OF NEW ZEALAND. IV 5
Specific differentiation. Readily distinguished from M. arenicolus, the only other known New Zealand species by the subterminal position of the caudal gland duct. The subterminal position of the caudal gland duct in conjunction with the regu- larly conoid tail, the regular arrangement of the subventral denticles and the absence of a pair of large, posterior subventral denticles, serve to distinguish this species from all others in the genus.
Type slides. Holotype and paratypes in nematode collection, Entomology Divi- sion, D.S.I.R., New Zealand. Paratype in slide collection, Nematology Department, Rothamsted Experimental Station, Harpenden, Herts., England, slide no. 147/4/1.
Type locality. Kumara Beach, Westland, N.Z.M.S.1. S 50151 741656, in stabi- lized sand ridge with Trifolium repens L., Hydrocotyle sp., Hypochoeris radi- cata L., Plantago sp., and Festuca novaezealandiae Cockayne. Soil: Mahinapua sands (imature podzolic loamy sands). Other localities: Ross, Westland in Trifolium repens L. — Anthoxanthum odo- ratum L. — Lolium perenne L. pasture; Reefton in Sphagnum swamp with Hypo- choeris radicata L.; Hongi's Track, in Beilschmiedia Tawa Benth. & Hook. f. — Knightia excelsa R. Br. forest litter; Waitaanga Saddle in liverworts and mosses in Tree-fern — Brachyglottis repanda Forst. — IVeinmannia racemosa Linn. f. forest; Wharekohe, in 18 year-old Paspalum dilatatum Poir — Lolium perenne L. — Trifolium repens L. pasture; Kiripaka in Beilschmiedia Taraire Benth. & Hook. f. — Vitex lucens T. Kirk — Dysoxylum spectabile Hook. f. forest litter.
Remarks. All localities where this species has been found either are, or in historic time have been forested areas. This species has not been found in natural grasslands areas, but has been found in grasslands induced by man.
CHECKLIST OF NEW ZEALAND MONONCHIDAE Mononchus composticola Clark, 1960 Cobbonchus pounarnua Clark, 1960 mesadenus Clark, 1960 Miconchris rex (Cobb, 1904) Andrassy, 1958
propapillatus Clark, 1960 Iotonchus basidontus Clark, 1960 Prionchulus muscorum (Dujardin, 1845) „ maragnus Clark, 1960 Chitw. & Chitw., 1937 ophiocercus Clark, 1960 Mylonchulus ubis n. sp. parazschokkei (Allgen, 1929)
51 arenicolus n. sp. Andnissy, 1958 Cobbonchus chauliodus Clark, 1960 percivali Clark, 1960
Allgen's (1929) record of lotonchus trichurus (Cobb, 1917) Andrassy, 1958 from Campbell Island is considered doubtful.
6 CLARK, THE MONONCHIDAE OF NEW ZEALAND. IV
ZUSAMMENFASSUNG
Die Mononchiden (Enoplida: Nematoda) Neu-Seelands 4. Die Gattung Mylonchulus (Cobb, 1916) Pennak, 1953
Zwei neue Arten der Gattung Mylonchulus werden beschrieben. Mylonchulus arenicolus n. sp. ist unterschieden durch den Besitz einer fast parallel-seitigen MundhOhle, fiinf Reihen subventraler Zahnchen, zwei kleiner subventraler Zahne und einem gebogenen fast konisch gefingerten Schwanz mit einer kaudalen Driisengang. M. ubis n. sp. ist charakterisiert durch die Anwesenheit regular angeordneter subventraler Zahnchen und dem Fehlen subventraler Zahne. Der Schwanz ist in der Regel konisch gebogen mit einer dorsalen, subterminalen Drilsengang.
REFERENCE
ALLGEN, C. (1929). Ober einige freilebende Moos-Nematoden, Nyt Mag. Naturvid. 67, 211-230. CLARK, W. C. (1960a). The oesophago-intestinal junction in the Mononchidae (Enoplida, Nema- toda). Nematologica 5, 178-183. (1960b). The Mononchidae (Enoplida: Nematoda) of New Zealand 1. The genera Mononchus Bastian, and Prionchulus Cobb. Nematologica, 5, 199-214. (1960c). The Mononchidae (Enoplida: Nematoda) of New Zealand. 2. The genus lotonchus (Cobb, 1916) Altherr, 1950. Nematologica 5, 259-273. (1960d). The Mononchidae (Enoplida: Nematoda) of New Zealand. 3. A review of the genus Cobbonchus Andrassy, 1958 with descriptions of new species, Nematologica 5, 274-283.
Received for publication: November 7, 1960